Answer:we need the pic bro
Explanation:
Liquid nitrogen is a very cold fluid form of nitrogen that is capable of freezing objects in very short periods of time. In fact, if a ping pong ball is placed in liquid nitrogen for a few minutes and then dropped on the floor, it shatters like glass.
What type of changes does the ball experience when it is frozen in the liquid nitrogen and then dropped on the floor?
A.
physical changes only
B.
neither physical nor chemical changes
C.
physical and chemical changes
D.
chemical changes only
plz don't give wrong asnwer
Answer:
Answer C physical and chemical
How many eight-packs of water would you need if 32 people
are attending your part and each consumed 2 bottles of
water?
Answer:
You would need 8 eight packs of water
Explanation:
32 x 2 (seeing as this is the amount of water each person consumes)
= 64 divided by 8 (the amount of water in each pack)
= 8 eight packs of water
(1.7 x 10-5 m) x (3.72 x 10-4 m) *
Answer:
The answer will be 1992/5 or 398.4
which gases are responsible for global warming?
Answer:
Greenhouse gas Chemical formula Global Warming Potential, 100-year time horizon
Carbon Dioxide
Methane
Nitrous Oxide
Chlorofluorocarbon
Explanation:
An actual measurement of a sample 3.5 M the measured value is 2.5 M what is the percentage error in the measurement
Answer: 29%
Explanation:
Answer:
b 29 percent
Explanation:
Atoms are generally held together by attraction between neutrons and protons (the strong interaction) and stabilized by electrons. As atoms increase in mass, it becomes easier for them to have too many or too few neutrons, leading to radioactive isotopes of certain elements. What factors might allow this to happen?
Answer:
im pretty sure the answer is: alpha decay, beta decay, and gamma decay.
Explanation:
Need Help ASAP
Thanks you
A student wants to burn a 1.25 mL sample of ethanol (C2H5OH, d = 0.789 g/mL) in a jar containing dry air. Assuming the air in the jar is at standard atmospheric pressure and room temperature (22 °C), what volume will the jar need to be in order to hold enough oxygen for complete combustion? Hint: Refer to the composition of dry air in the previous question. (a) Write a balanced chemical reaction for the combustion of ethanol. (b) Calculate the moles of oxygen needed to completely combust the ethanol. (c) Calculate the partial pressure of oxygen in the jar. (d) Calculate the volume of oxygen (in L) needed in t
Answer:
The volume of the jar needed in order to hold enough oxygen for complete combustion is 24.2 L
(a) C₂H₅OH + 2O₂ -------> 2CO₂ + 3H₂O
(b) The moles of oxygen needed to completely combust the ethanol is 0.0429 moles
(c) The Partial pressure of oxygen is 4346.84 Pa
(d) the volume of oxygen (in L) needed in the jar is 1.038 L
Explanation:
Given;
volume of ethanol, V = 1.25 mL
density of ethanol, ρ = 0.789 g/mL
mass of ethanol, m = ρV = (1.25 mL) x (0.789 g/mL) = 0.986g
The volume of the dry air is calculated as;
[tex]P_d = \rho _d R_d T\\\\P_d = (\frac{M_d}{V_d} )R_d T\\\\V_d = (\frac{M_d}{P_d} )R_d T\\\\V_d = (\frac{0.02897 \ (kg)}{101325 \ (Pa)} )*287 \ (J/K.kg)* 295\ (K)\\\\V_d = 0.0242 \ m^3\\\\V_d = 24.2 \ L[/tex]
(a) a balanced chemical reaction for the combustion of ethanol
C₂H₅OH + 2O₂ -------> 2CO₂ + 3H₂O
(b) The moles of oxygen needed to completely combust the ethanol.
[tex]=0.986 g \ C_2H_5OH *(\frac{1 \ mol \ C_2H_5OH}{46g \ C_2H_5OH} )*(\frac{2 \ Mol \ O_2}{1 \ mol \ C_2H_5OH} )\\\\ = 0.0429 \ mols.[/tex]
(c) the partial pressure of oxygen in the jar
Total pressure of air in the jar, Pt = 101,325 Pa
Partial pressure of oxygen = nPt
= 0.0429 x 101,325 Pa = 4346.84 Pa
(d) the volume of oxygen (in L) needed in the jar
Total volume of air in the jar = 24.2 L
The fraction of this volume by oxygen = 0.0429 mols x 24.2 L = 1.038 L
Dry air is composed of many molecules and compounds. The major quantity of molecules present in the dry air is Nitrogen, followed by oxygen, argon, carbon dioxide and many more. Dry air also has some amount of water vapor in it.
The volume of the jar needed to hold enough oxygen for complete combustion can be calculated by:
Volume of ethanol= 1.25 mlDensity of ethanol = 0.789 g/mlMass of ethanol can be calculated by:= density × volume
= 1.25 ml x 0.789 g/ml
= 0.986 g
The volume of the dry air is calculated by the following:
[tex]\text{P}_d &= \rho_d \text{R}_d \text{T}[/tex]
[tex]\text{P}_d &= \dfrac{{\text M}_d}{\text{V}_d}} \text{R}_d \text{T}[/tex]
[tex]\text{V}_d &= \dfrac{{\text M}_d}{\text{V}_d}} \text{R}_d \text{T}[/tex]
[tex]\text{V}_d &= 0.0242\; m^{3}[/tex]
[tex]\text{V}_d &= 24.2\;\text L[/tex]
Hence, the volume of the dry air is 24.2 L.
a. Balanced chemical equation for the combustion of ethanol can be written as:
C₂H₅OH + 2 O₂ -------> 2 CO₂ + 3H₂O
One molecule of ethanol reacts with two molecules of oxygen to produce two molecules of carbon dioxide and three water molecules.
b. To calculate the moles of oxygen needed for complete combustion of ethanol can be calculated as:
[tex]\begin{aligned}&=0.986g\;\text{C}_2\text{H}_5\text{OH}\times\left(\frac{1\;\text{mol}\;\text{C}_2\text{H}_5\text{OH}}{46\;g\;\text{C}_2\text{H}_5\text{OH}} \right )\times\left(\frac{2\;\text{Mol\;O}_2}{1\;\text{mol}\text{C}_2\text{H}_5\text{OH}} \right )\\&=0.0429\text{mols} \end{aligned}[/tex]
Hence, 0.0429 moles of oxygen will be needed to completely burn ethanol.
c. The partial pressure of the oxygen in the jar can be calculated by the following formula:
Given,
Total pressure of air in the jar (Pt) = 101,325 PaThe partial pressure of oxygen:= nPt
= 0.0429 x 101,325 Pa
= 4346.84 Pa
Hence, the partial pressure of oxygen will be 4346.84 Pa.
d. The volume of oxygen (in L) needed in the jar can be calculated using the volume of the jar.
The total volume of air in the jar = 24.2 LThe fraction of this volume by oxygen:= 0.0429 moles x 24.2 L
= 1.038 L
Therefore, the volume of the jar needed to hold enough oxygen for complete combustion is 24.2 L.
To learn more about combustion reaction follow the given link:
https://brainly.com/question/25092860
Determine whether each statement is a description of a physical property or a chemical property. Please check the box that applies.
Copper conducts heat well.
physical
chemical
Alcohol has a sweet odor.
physical
chemical
Answer:
Copper conducts heat well- physical
Alcohol has a sweet door- physical
Explanation:
Answer:
a, a
Explanation:
A 90-m3 basement in a residence is found to be contaminated with radon coming from the ground through the floor drains. The concentration of radon in the room is 1.5 Bq · L−1 (becquerels per liter) under steadystate conditions. The room behaves as a CMFR, and the decay of radon is a first-order reaction with a decay rate constant of 2.09 × 10−6 s−1. If the source of radon is closed off and the room is vented with radon-free air at a rate of 0.14 m3 · s−1, how long will it take to lower the radon concentration to an acceptable level of 0.15 Bq · L−1?
Answer: it will take 24.6467 min to lower the radon concentration to an acceptable level of 0.15Bq.L^-1
Explanation:
To calculate the required time, we make use of the formula
Cout = Coexp [ - ( 1/θ + k ) t ] .........lets call this equation 1
where Co is the concentration of radon( 1.5Bq.L^-1 ), Cout id the allowable radon concentration( 0.15Bq.L^-1), k is the radon decay rate constant( 2.09 * 10^-6 s^-1 ), θ is the theoretical detention time and t is the time required to lower the radon concentration.
first we find θ which is the theoretical detention time using the expression
θ = _V / Q
_V is the volume of basement (90 m^3) and Q is the rate of free air (0.14 m^3.s^-1)
so we substitute
θ = 90 / 0.14
θ = 642.857 s
Now we substitute all our values into equation 1
Cout = Coexp [ - ( 1/θ + k ) t ]
0.15 = 1.5exp [ - ( 1/642.857 + (2.09 * 10^-6) ) t ]
divide both LHS and RHS by 1.5
0.15/1.5 = exp [ - ( 0.001555 + 0.00000209)t ]
0.1 = exp[ - ( 0.001557)t ]
next we take the natural log of both sides
In 0.1 = In [ exp( -0.001557t )]
-2.3025 = - 0.001557t
t = 2.3025 / 0.001557
t = 1478.8053 sec
so we convert to minutes
t = 1478.8053 / 60
t = 24.6467 min
therefore it will take 24.6467 min to lower the radon concentration to an acceptable level of 0.15Bq.L^-1
The lungs are connected to the trachea by _____. bronchi windpipes alveoli capillaries
Answer:
Bronchi
Explanation:
The trachea divides into air tubes called the bronchi, which connects it to the lungs.
Answer:
bronchi
Explanation:
The arrows in the chart below represent phase transitions.
Solid
Liquid
16
Gas
Which arrows represent the phase transitions in which heat energy is gained?
1, 2, and 3
2,3, and 5
3, 4, and 5
4,5, and 6
Answer:
A: 1, 2, and 3
Explanation:
mY ANSWER GOT DELETED ITS WHAT I SAID BEFORE ITS ON EDGE2020
Answer:
A. 1, 2, and 3
Explanation:
Correct on Edge 2022!!!
Good luck everyone, you got this! Have a great day!
What is the pH of an aqueous solution with a hydrogen ion concentration of [H+]=9.2×10−6 M?
Answer:
The answer is 5.04Explanation:
The pH of a solution given it's hydrogen ion concentration can be found by using the formula
[tex]pH = - log( {H }^{ + } ) [/tex]where
[tex]{H }^{ + }[/tex] is the hydrogen ion concentration
From the question
[tex]{H }^{ + }[/tex] = [tex]{9.2 × 10 }^{ - 6}[/tex] M
The pH of the solution is
[tex]pH = - log(9.2 \times {10}^{ - 6} ) \\ = 5.03621217...[/tex]
We have the final answer as
5.04Hope this helps you
In which of the following experiments would the results be most reliable?
A.
an experiment in which the trials were repeated many times
B.
an experiment which contained no controls
C.
an experiment which contained several variables
D.
an experiment in which the trial was repeated a few times
Answer:
A
Explanation:
When doing an experiment you want the most trials and most controls possible. It is impossible to get good data while testing multiple variables at once.
Lithium (Li) is in the 2nd row, so the 1st row is already full (1s2). Since lithium (Li) is in the 2nd row, the s-block, and the 1st column of that block, the electron configuration of lithium (Li) is
The electronic configuration of lithium is 1 s² 2s¹ as it has 1 electron in 2 s subshell it is a s-block element.
What is electronic configuration?
Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
Learn more about electronic configuration,here:
https://brainly.com/question/29757010
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Help out 1 and 2, Will mark brainliest !!
what happens during the dissolution of wax in kerosene
Answer:
The wax will totally dissolve in the kerosene.
Explanation:
Hello.
In this case, since wax is more specifically known as paraffin wax which is a heavy-highly nonpolar organic compound which is largely insoluble in water due to its nonpolar nature, when dissolved in kerosene which is a highly nonpolar organic solvent we can infer that the dissolution process will rapidly undergo even at normal conditions due to the intermolecular forces joining them.
Therefore, when wax is dissolved in kerosene a complete dissolution is evidenced due to their common nature.
Best regards.
Why are nutrient molecules important?
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures, such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted to smaller molecules in the process of releasing energy, such as for carbohydrates, lipids, proteins, and fermentation products (ethanol or vinegar), leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host.
What happened to the arrangement and the speed of water molecules when liquid water turns into ice?
Answer:
Point out that when water freezes, the water molecules have slowed down enough that their attractions arrange them into fixed positions. Water molecules freeze in a hexagonal pattern and the molecules are further apart than they were in liquid water.
Answer: Point out that when water freezes, the water molecules have slowed down enough that their attractions arrange them into fixed positions. Water molecules freeze in a hexagonal pattern and the molecules are further apart than they were in liquid water.
Explanation: The molecules in the rice would be vibrating!!!!!!
Torque can be calculated by multiplying the force (N) applied at 90∘ to the lever arm at a distance (m) from the pivot point (point of rotation), the compound SI unit for the torque is N⋅m. If the force (at 90∘ to the lever arm) applied is 15 N and it is applied at 2.0 m from the pivot point (point of rotation), what is the torque on the lever?
Answer:
F=15 N
Moment arm=2 m
torque=Fl=15x2=30 Nm
Explanation:
Prions are proteins with the ability to generate more prions by causing other proteins to misfold into a similar shape. Since prions are proteins, they have a genetic sequence associated with them and their ability to create more prions allows them to reproduce. Why aren’t prions considered alive?
are theories incomplete temporary ideas
Answer:
Yes , because they are not yet proven.
Hope this helps-xoxo
Answer:yes
Explanation:ideas are theoris the are incomplete
In this experiment, you are given 3 unknown metals and will determine their identities by finding their densities. The possible metals are silver, rhodium, and platinum, with densities of 10.5, 12.4, and 21.45 g/cm3 respectively. First, you must determine the mass of a sample of one of the metals. Using the electronic balance, record the mass of the weigh boat. Pour approximately 50 g of the metal onto the weigh boat and record the combined mass. Then, pour approximately 10 mL of distilled water into a 25 mL graduated cylinder, and record the volume of water added. Pour the sample of metal from the weigh boat into the graduated cylinder, and record the combined volume. Take care to always record the volume from the bottom of the meniscus of the water, not the upper curved edges. From this, calculate the density of the metal. Repeat this process two more times for the same metal, using samples of approximately 75 g and 100 g respectively. Using these three data points, calculate the average density of the metal. Repeat this procedure for the other two metals to calculate their average densities. From these, identify the metals by comparing them to the given values of the densities of silver, rhodium, and platinum.
Answer:
Explanation:
This question is a practical question that needs to be practiced in a lab. However, the guide below will assist in answering the question.
Let's assume our unknown metals are X, Y and Z. The unknown metals will be weighed using a weight boat on an electronic balance. Hence, the mass of the weight boat will have to be measured if you do not wish to "tare" the balance when the weight boat is on it - the instruction in the question prefers the former.
Assuming the mass of the weight boat is measured to be 10g (and then recorded), the unknown is added to it until the balance reads 60g.
Hence,
The total mass recorded on the balance = the mass of the weight boat + 50g of the unknown sample.
When the unknown sample is then poured into the 10 ml of water in the 25 ml graduated cylinder, the volume of water will rise. The final volume of the water must be recorded in order to calculate the change in volume.
change in volume = Final volume recorded - 10 ml (volume of water before the sample was added)
Density of the unknown solid = mass of unknown solid (50 g) ÷ change in volume
This process is done three times (and all values recorded) for each metal (X, Y and Z). And the process is also done (three times with all values recorded) with different masses of 75 g and 100 g of the unknown sample.
In order to calculate the average density of each unknown metal, the following can be done.
The average density of unknown metal X of 50g (assuming it's DX₁) = (density obtained after first experiment + density obtained after second experiment + density obtained after third experiment)/3
The average density of unknown metal X of 75g (assuming it's DX₂) = (density obtained after first experiment + density obtained after second experiment + density obtained after third experiment)/3
The average density of unknown metal X of 100g (assuming it's DX₃) = (density obtained after first experiment + density obtained after second experiment + density obtained after third experiment)/3
The average density of metal X = (DX₁ + DX₂ + DX₃)/3
The same calculations (above) is repeated for metals Y and Z.
From the question, platinum has the highest density, followed by rhodium and then silver. Hence, after the experiments and then the calculations, the unknown metal with the highest average density will be assumed to be platinum and the next one will be assumed to be rhodium while the one with the least average density will be assumed to be silver.
(Exercise 5.2.14 modified) A common method used to produce bleach (sodium hypochlorite) is by the reaction Cl2 + 2NaOH NaCl + NaCl + H2O. Chlorine gas is bubbled through an aqueous solution of sodium hydroxide, after which the desired product is separated from the NaCl (by product). A water-NaOH solution that contains 1200 lb of pure NaOH is reacted with 800 lb of gaseous Cl2. The NaOCl formed weighs 600 lb. a. What was the limiting reactant
Answer:
Chlorine is limiting reactant
Explanation:
Based on the reaction:
Cl₂ + 2NaOH → NaClO + NaCl + H₂O
1 mole of chlorine reacts with 2 moles of NaOH
To find limiting reactant, we need to determine the moles of the reactants:
Moles Cl₂ -Molar mass: 70.9g/mol-:
800lb Cl₂ * (453.6g / 1lb) * (1mol / 70.90g) =
5118 moles Cl₂
Moles NaOH -Molar mass: 40g/mol-:
1200lb NaOH * (453.6g / 1lb) * (1mol / 40g) =
13608 moles NaOH
For a complete reaction of 13608 moles of NaOH you need:
13608 moles NaOH * (1mol Cl₂ / 2 moles NaOH) = 6804 moles of Cl₂
As the solution contains just 5118 moles of chlorine,
Chlorine is limiting reactantBeryllium-9
Neutrons:
Protons:
Electrons:
Answer:
Neutrons - 5
Protons - 4
Electrons - 4
Explanation:
Beryllium (Be) is the 4th element on the Periodic Table.
It has 4 protons and 4 electrons (neutral charge)
Atomic Mass = # of Protons + # of Neutrons
9 = 4 + x
x = 5 Neutrons
How many electrons would Magnesium with a -1 charge have?
When matter changes from a solid to liquid or from liquid to gas, what kind of change takes place?
Answer :-
Physical change
Which of the following is an inference?
1. the sky is blue.
2. air pollution is responsible for the colors we see during a sunset.
3. when I touch a glass of water with ice it is cold.
4. sugar is sweet.
Answer:
2) is an inference
Write the electron configuration and Noble gas configuration for each element.
1. F
2. CI
3. Br
4. Zr
5. Ga
6. SC
7. Ru
8. Cd
Answer:
1is the answer to that one day F
Acetone is produced from 2-propanol in the presence of dioxygen and the photocatalyst TiO2 when the reactor is irradiated with ultraviolet light. For a reaction carried out at room temperature in 1.0 mol of liquid 2-propanol containing 0.125 g of catalyst the following product concentrations were measured as a function of irradiation time. Calculate the first order rate constant.
Reaction Time min 20 40 60 80 100 120 140 160 180
Acetone Produced 1.9 3.9 5.0 6.2 8.2 10 11.5 13.2 14.0
Answer:
20 30 40 50 is the answer to that one day
