What amount of ice must be added to 250 g of water at 15°c to cool the water to 0°c and have no ice left
Answer:
[tex]\mathbf{m= 47 \ g}[/tex]
Explanation:
The heat needed to melt ice [tex](q_1)[/tex] + heat needed to cool water [tex](q_2)[/tex] = 0
[tex]m\Delta H_{fusion} + mc \Delta T = 0[/tex]
[tex]m \times 333.55 J g^{-1} + 250 \ g \times 4.184 \ Jg^{-1 \ 0 } \times (-15.0 \ ^0 C) = 0[/tex]
[tex]m \times 333.55 J g^{-1} =15690[/tex]
[tex]m=\dfrac{15690 \ J }{333.55 J g^{-1} }[/tex]
[tex]\mathbf{m= 47 \ g}[/tex]
15. On some occassions, more than half of the moon is dark.
O
a. True
O b. False
The temperature of a substance is a measure of the
1.
average kinetic energy of its particles
2.
average potential energy of its particles
3.
ionization energy of its particles
4.
activation energy of its particles
Answer:
1. average kinetic energy of its particles
Explanation:
The temperature of a substance is a measure of the average kinetic energy of its particles.
The average kinetic energy of the particles of a substance is directly proportional to its temperature. This is one of the premise of the kinetic theory of gases.
When thermal energy is supplied to a substance, the molecules gains kinetic energy. As the kinetic energy increases so also the temperature of the substance. So, we see that kinetic energy and temperature are connected through the thermal energy acquired by the substance.this is simple, I just want to check my answer for this
What is the correct FORMULA for Aluminum borate?
Answer:
I think it's K2Al2B2O7
Aluminum Borate or Aluminum Boron Oxide is AlBO₃
on reaction:
BO₃⁻³ + Al⁺³ ==> AlBO₃
Which is more dense:
(b)Oxygen or air?
Answer:
I think air is more denser than oxygen
When 1.008 g of hydrogen reacts with chlorine in a calorimeter containing 500.00 g water, the
temperature rises from 25.00 °C to 29.24 °C. Calculate water for the process. (Remember,
change in T determines (1) the number of significant digits and (2) the sign of your
answer.)
H2(g) + Cl2(9) --> 2HCl(g)
A) -8.870 kJ
B) +8870 J
C) -8870 J
D) +8.870 kJ
The heat released by reaction : C) -8870 J
Further explanationGiven
1.008 g of hydrogen
500.00 g water
The temperature rises 25.00 °C to 29.24 °C
Required
energy required
Solution
Q absorbed by water :
Q = m.c.Δt
Q = 500 g x 4.18 J/g C x (29.24-25)
Q = 8870.08 J
The reaction to produce HCl is an exothermic reaction (releasing heat), so that Q is negative
Q water = -Q HCl = -8870.08 J
-
FeCl2 +
Cl2 →
FeCl3
How do I balance this?
Answer:
2FeCl2+Cl2→2FeCl3
Explanation:
Molecules are formed from ?
wood is A)element B)compound C)mixture
Finish this formula: Speed = _______ divided by time
Answer:
Distance
Explanation:
Speed= Distance/ Time
Answer:
Distance would be the answer! :)
Calculate the mass of 3 moles of CCI4
Answer:
So one mole of ccl4 contains 152 grams. it implies that 3 moles of ccl4 contains 152 * 3 grams. it is equal to 456. grams.
Explanation:
Hope this helps
i need help but the answer choice is (A. protists) (B.lichens) C. flagellates) (D.yeast )
Answer:
A
Explanation:
please mark me as brainlist and follów me too
Answer:
The Lichen Symbiosis
Lichens are made up of two or more closely interacting organisms, a fungus, and one or more partners, called photobionts. The photobiont may be an alga and/or cyanobacteria, both of which can produce simple sugars by photosynthesis.
Explanation:
What is an air pressure system?
Answer:
"The number of air molecules above a surface determines air pressure. As the number of molecules increases, they exert more pressure on a surface, and the total atmospheric pressure increases. By contrast, if the number of molecules decreases, so too does the air pressure."
Hello, I need some help writing a paragraph about the water cycle! If u can write a paragraph EXPLAINING the water cycle i would be so happy. But if u do that make sure you use all of the Vocabulary! Please help
Answer:
The water cycle, also known as the hydrologic cycle or the hydrological cycle, describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor. Hope this helps, mark as brainliest please!
Please help, I will give brainliest.
Answer:
A. manganese change from +7 to +2
Explanation:
Reduction means a gain of electrons, which means the oxidation number will go down or the charge goes down basically or become more negative charge. On the left, Mn has +7 in MnO4-. On the right, it has 2+, so it has been reduced.
1. 32.5grams of NaOH (sodium hydroxide) reacts an excess of CO2 (carbon dioxide).
2NaOH(s) + CO2(g) → Na2CO3(s) + H2O(1)
a.
What is the theoretical yield of Na2CO3 in grams? Answer: 43.1g Na2CO3
b.
If 16.45 g of Na2CO3 is formed, what is the percent yield? Answer: 38.2%
a. 43.1 g
b. 38.2%
Further explanationGiven
32.5 grams of NaOH
Required
The theoretical yield of Na₂CO₃
The percent yield
Solution
Reaction
2NaOH(s) + CO₂(g) → Na₂CO₃(s) + H₂O(l)
mol NaOH :
= mass : MW
= 32.5 : 40 g/mol
= 0.8125
mol Na₂CO₃ from the equation :
= 1/2 x mol NaOH
= 1/2 x 0.8125
= 0.40625
a.
Mass Na₂CO₃ :
= mol x MW Na₂CO₃
= 0.40625 x 106 g/mol
= 43.0625≈43.1 g
b. % yield = (actual/theoretical) x 100%
%yield = 16.45/43.1 x 1005
%yield = 38.17%≈38.2%
For the balanced equation shown below, if the reaction of 77.0 grams of CaCN2 produces 26.1 grams of NH3, what is the percent yield?
CaCN2+3H2O=>CaCO3+2NH3
%yield = 86.93%
Further explanationGiven
Reaction
CaCN₂+3H₂O=>CaCO₃+2NH₃
Required
The percent yield
Solution
mol CaCN₂(MW= 92 g/mol) :
= mass : MW
= 77 g : 92 g/mol
= 0.834
From equation, mol NH₃ :
= 2/1 x mol CaCN₂
= 2/1 x 0.834
= 1.668
Mass NH₃(theoretical):
= 1.668 mol x 18 g/mol
= 30.024 g
% yield = (actual/theoretical) x 100%
%yield = (26.1/30.024) x 100%
%yield = 86.93%
a magnet has a north and south pole labeled in the drawing student A thinks that if you cut a magnet in half each ew parts will separate into either the north or the south poles is the student correct
Answer:
The student is Incorrect
Explanation:
Even if you break a magnet the poles still remains same. There is no
difference in the magnet Both north and south pole will be there even if you
cut it in to small pieces when you cut it into pieces, if suppose you break 2
magnets and put north and north together it will repel whereas if there are
different poles like north and south it will attract, so even if you break one
single magnet the different poles will attract, Hence the student is incorrect.
Please mark me as brainliest
Thank you :)A scientist is trying to develop a more efficient way to recycle paper this type of chemistry is known as
Answer:
Green chemistry
Explanation:
Green chemistry is the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. Green chemistry applies across the life cycle of a chemical product, including its design, manufacture, use, and ultimate disposal(EPA, 2017).
Green chemistry, also called sustainable chemistry, is an area of chemistry and chemical engineering focused on the design of products and processes that minimize or eliminate the use and generation of hazardous substances(wikipedia).
Thus, any research in chemistry geared towards waste reduction(such as more efficient methods of paper recycling) and recycling of other materials as well as placing less demands on the natural sources of materials is known as green chemistry or sustainable chemistry.
2.
How many moles are contained in 0.800 g of calcium chloride (CaCl2)?
Even a small sample of matter may contain millions and millions of atoms, molecules or ions. To represent these entities the unit mole is used. The number of moles in 0.800 g of CaCl₂ is
What is number of moles?One mole of a substance is defined as that amount of it which contains as many particles or entities as there are atoms in exactly 12 g of Carbon - 12 is called the mole.
The equation which is used to calculate the number of moles is:
Number of moles (n) = Given mass / Molar mass
The mass of one mole of molecules of a substance is called the molar mass.
Here the given mass of CaCl₂ is 0.800 g and the molar mass is 110.98 g/mol. Then,
n = 0.800 g / 110.98 g / mol = 0.0072 mol
Thus the number of moles is 0.0072 mol.
To know more about moles, visit;
https://brainly.com/question/15209553
#SPJ2
A sample of silver has a mass of 21 grams
and a volume of 2 cm3. What is the density
of silver?
Answer:
[tex]density \: of \: the \: silver = \frac{mass}{volume} = \frac{21}{2} \\ = 10.5 \: gram {(cm)}^{ - 3} [/tex]
10.5 gram(cm)^-3 is the right answer.Explanation:
recall that density is equal to mass/volume :21÷2= 10.5g/cm3
The name is As2S5 is?
Answer:
i dont no......
Explanation:
...........
help please! it’s due in a few
Answer:
C
Explanation:
Electrons are negatively charged with a charge of -1e. They can move between atoms while protons stay in the atom.
How many grams is 5.4x10 to the 23 molecules of al2o3?
Answer:
91.49 grams
Explanation:
No of molecules = no of moles × Avogadro's number
No of moles = No of molecules / Avogadro's number
Number of moles = 5.4×10^23/6.02×10^23
Number of moles = 0.897 moles of Al2O3
Number of moles = mass in gram / molar mass
Mass in gram = number of moles× molar mass
Mass in gram = 0.897× 102
91.49 grams
Identify the group of elements with the same outermost energy level
a)H, He
b)N, P, As, Bi
c)Rb, Sr, Y, Zr
d)B, Si, As, Te, At
Answer:
A
Explanation:
b) N, P, As, Bi
Elements in the same group all have the same number of valence electrons and therefore similar chemical properties. Valence electrons help in predicting chemical reactions.So all the atoms of a given element have the same energy levels because they have the same numbers of electrons and protons.N, P, As, Bi for this group of elements, all these elements belongs to same group i.e. group 15. Group 15 has total 5 valence electrons.Electronic configuration = ns²np³All these elements will have same outermost energy level.Learn more:
brainly.com/question/371590
what type of wave is shown ?
Which behavior is an example of how animals defend their territory?
O A. Rhinoceros males urinate to mark the area where they live.
OB. Several dolphins swim around a school of fish and take turns feeding.
OC. Hyenas and lions compete for prey. O D. A bee shares the location of food with other bees.
Answer: A
Explanation: because It shows how they mark there territory by unreining
Answer: O A. Rhinoceros males urinate to mark the area where they live.
Explanation:
O B. Is an example of animals working to together.
O C. This is competition rather than defending territory.
O D. Again an example of animals working together.
Make sure to study, as the text provided for A. P. E. X is extremely helpful! Don’t stress, make sure to stay hydrated, have self care, and remember self care isn’t just proper hygiene make sure you take care of your well being while making sure you’re mindful that you are just a person, have a good day! I love ya’ll and I’m proud of ya!
To clarify the answer is correct as I have the same Test (CST): Response to Stimuli:
How many moles of Al2O3 are formed from the reaction of 6.38 mol O2 and 9.15 mol Al?
Answer:
The number of moles of Al2O3 formed is about 4.25 moles
Explanation:
why did modern's say atoms are divisible
Write down a question about yeast fermentation that can be answered through scientific investigation.
Explanation:
Alcoholic fermentation converts one mole of glucose into two moles of ethanol and two moles of carbon dioxide, producing two moles of ATP in the process. The overall chemical formula for alcoholic fermentation is: C6H12O6 → 2 C2H5OH + 2CO
Answer:
1. If you leave yeast fermentation out for 3 days what happens?
2. If you put yeast fermentation out in the sun will it still work?
Explanation:
These can be answered through scientific investigation.
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