Pls help, science 8th grade question, #11 thx :)
Calculate the mass of 3.5 moles of H2O
63 g H₂O
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
3.5 mol H₂O
Step 2: Identify Conversions
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 3.5 \ mol \ H_2O(\frac{18.02 \ g \ H_2O}{1 \ mol \ H_2O})[/tex]Divide/Multiply: [tex]\displaystyle 63.07 \ g \ H_2O[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
63.07 g H₂O ≈ 63 g H₂O
Part 1
For 671 g of butadiene (C4H6) calculate the number of moles.
Answer in units of mol.
Part 2
Calculate the number of molecules.
Answer in units of molec.
Answer:
74.73 ×10²³ molecules
Number of moles = 12.41 mol
Explanation:
Given data:
Mass of C₄H₆ = 671 g
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles:
Number of moles = mass/molar mass
Number of moles = 671 g/ 54.091 g/mol
Number of moles = 12.41 mol
Number of molecules:
1 mole contain 6.022×10²³ molecules
12.41 mol × 6.022×10²³ molecules / 1 mol
74.73 ×10²³ molecules
Why is it necessary for the radio of atoms to be expressed as the distance between the nuclei of the two identical atoms bonded together?
A block of metal has a volume of 14.0 in' and weighs 5.28 lb.
Part A
What is its density in grams per cubic centimeter?
Express the density in grams per cubic centimeter to three significant figures.
Explanation:
1inch = 2.54cm
1inch^3= 2.54³ = 16.38cm^3
13.4cm^3 = 13.4*16.38 = 219.5867 cm^3
1lb = 454g
5.14lb = 5.14*454g/lb = 2,333.6g
density g/cm^3 = 2,333.6/219.6cm^3
density = 10.6265938 g/cm^3
to three significant figures:
density = 10.6g/cm^3
How many moles are in 25.58 grams of H20? SHOW WORK
Answer:
1.42 moles
Explanation:
25.58 g of H₂O .
Molecular weight of water = 2 x 1 + 16 = 18
1 mole of water = 18 g of water
18 g of water = 1 mole
25.58 g of water = 25.58 / 18 mole
= 1.42 moles .
Plz guys help me plz
Explanation:
Can you edit your question and get a better pic because I cant see anything. Its blurry.
Why the copper is able to replace the silver, but the reverse reaction will not result in a replacement reaction?
Answer:
Copper is more reactive and higher in the activity series
Explanation:
Copper is able to replace the silver in a replacement reaction because it is more reactive and higher in the activity series.
Substances or ions that are higher in the activity series are typically more reactive than those ones below them.
In like manner, they are able to replace the lowers ones in a chemical reaction due to their higher reactivity potential.
A less reactive element and a lower one in the activity series cannot displace a higher one in the series.
Please help and try to explain if you can!
Answer: 4.76 * 10^2
476.
you bring the ending decimal to the first number and it takes you two hops to get the first number so that's what you put in the box after the 10
2. Put the following steps of scientific inquiry in order, please number 1‐3.
_______Make an observation
_______ Ask a question
_______ Form a hypothesis
When fat comes in contact with sodium hydroxide, it produces soap and glycerin. Determine whether this is a physical change or a chemical change. Explain your
Answer:
This is a chemical change because new substances are formed with different properties and identities.
The oxidation of Cu₂O(s) to CuO(s) is an exothermic process:
2 Cu₂O(s) + O₂(g) → 4 CuO (s) ∆H = -292.0 kJ・mol⁻¹
Calculate the work done when 6.50 mol of Cu₂O(s) undergo oxidation at STP.
Answer:
w = 7376.6 J
Explanation:
To calculate the work done in the system, we need first to calculate the number of moles of all compounds.
The following expression, that comes from the 1° law of thermodynamic, will help you to get the work:
w = ΔnRT
Where:
Δn: difference in the number of moles between products and reactants
R: constant universal of gases (8.314 J / mol K)
T: Temperature in Kelvin.
As we are doing this reaction in STP, then the Pressure is 1 atm, and temperature is 0 °C or 273 K.
Now, we already have the moles of Cu₂O, let's see, according to the balanced reaction, how many moles we should have of O₂ and CuO.
If 1 mole of O₂ reacts with 2 moles of Cu₂O then 6.5 moles of Cu₂O will be:
moles O₂ = 6.5 moles Cu₂O * (1 mole O₂/2 moles Cu₂O) = 3.25 moles O₂
If 2 moles of Cu₂O produces 4 moles of CuO, then 6.5 moles will be:
moles CuO = 6.5 moles Cu₂O*(4 moles CuO/2 moles Cu₂O) = 13 moles CuO
Now that we have the moles, let's calculate the value of Δn.
Δn = moles product - moles reactants
Δn = 13 - (6.5 + 3.25) = 3.25 moles
Now, we can calculate the work done in the system:
w = 3.25 * (8.314 * 273)
w = 7376.6 J or 7.3766 kJHope this helps
How (and where) does oceanic lithosphere (crust) form?
Answer:
Oceanic lithosphere forms at midocean ridges, where hot magma upwells, and then cools to form plates as the material moves away from the spreading center. As the plate cools, heat flow decreases and the seafloor deepens
Explanation:
Brainliest plzzzzzzz
Describe the environmental impacts that are involved during the design, research and development, and marketing phases of cell phones.
Answer:
joe mama
Explanation:
400 + 20 + 420
How much of a 500 gram sample of potassium-42 is left after
62 hours? The half-life of K-42 is 12.4 hours?
Answer:
The correct answer is - 15.625
Explanation:
The half-life is the time it takes to decay half value or quantity of its initial quantity or value. It is given that,
The half-life of K-42 = 12.4 hours
The initial value of K-42 = 500 gm
After 62 hours the value of k-42 = ?
The number of half cycle = 62*1/12.4 = 5,
therefore it will have 5 half-lives
initial - 500
1st half life - 500/2 = 250
2nd - half life - 250/2 = 125
3rd half life - 125/2 = 62.5
4th half life - 62/2 = 31.25
fifth half life - 31.25/2 = 15.625
Thus, the correct answer is =15.625g
15.625 g of a 500 gram sample of potassium-42 with 12.4 hours of Half -life is left after 62 hours.
The half-life is the time after which half of the initial quantity of a radioactive substance is left .
Given here,
The half-life of K-42 = 12.4 hours
The initial quantity of K-42 = 500 gm
The final quantity after 62 hours = ?
The number of half cycle
[tex]\bold { = 62\times \dfrac 1{12.4} = 5,}[/tex]
Thus the number of half life cycles in 62 hours is 5,
After 1 half life [tex]\bold {= \dfrac {500}{2} = 250}[/tex]
After 2 half lives [tex]\bold {= \dfrac {250}{2} = 125}[/tex]
After 3 half lives [tex]\bold {= \dfrac {125}{2} = 62.5}[/tex]
After 4 half lives [tex]\bold {= \dfrac {62.5}{2} = 31.25}\\[/tex]
After 5 half lives [tex]\bold {= \dfrac {31.25}{2} = 12.625}\\[/tex]
15.625 g of a 500 gram sample of potassium-42 with 12.4 hours of Half -life is left after 62 hours.
To know more about Half life,
https://brainly.com/question/4483570
. If 55.5 g of aluminum is heated to 95.0 °C and placed into 500.0 g of water at 30.0°C , What
is the final temperature of the system? Cp of aluminum is.900J/gºC
The final temperature of the system : 31.5 °C
Further explanationGiven
55.5 g Al, 95 C
500 g water, 30 C
C Al = 0.900 J/gºC
Required
the final temperature
Solution
Q in = Q out
Q absorbed = Q released
Q water = Q Aluminium
[tex]\tt 500\times 4.186\times (t-30)=55.5\times 0.9\times (95-t)\\\\2093t-62790=4702.5-49.5t\\\\2142.5t=67492.5\rightarrow t=31.5^oC[/tex]
1. 2.0 mL/s x 4.0 hrs = ? L
How do you do this conversion problem
Answer:
29 L.
Explanation:
Hello!
In this case, considering that we are performing a conversion by which the time should be cancelled out to obtain liters, we first need to convert the seconds on bottom to hours and then the volume on top to liters, just a shown down below:
[tex]2.0\frac{mL}{s} *\frac{1L}{1000mL} *\frac{3600s}{1hr}*4.0hr\\\\=28.8L[/tex]
Which turns out 29 L with 2 significant figures.
Best regards!
Determine the mass of oxygen that is needed to react with 33 grams of phosphorus.
4P + 5 O2 → 2 P205
A
27.3 grams O2
B
1.33 grams O2
С
213 grams 02
D
42.6 grams 02
Answer:
D = 42.6 g
Explanation:
Given data:
Mass of oxygen needed = ?
Mass of phosphorus react = 33 g
Solution:
Chemical equation:
4P + 5O₂ → 2P₂O₅
Number of moles of phosphorus:
Number of moles = mass/molar mass
Number of moles = 33 g/ 30.97 g/mol
Number of moles = 1.065 mol
now we will compare the moles of P and oxygen.
P : O₂
4 : 5
1.065 : 5/4×1.065 = 1.33mol
Mass of oxygen needed:
Mass = number of moles × molar mass
Mass = 1.33 mol × 32 g/mol
Mass = 42.6 g
what is thermal energy
Answer:
Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy. A whole branch of physics, thermodynamics, deals with how heat is transferred between different systems and how work is done in the process (see the 1ˢᵗ law of thermodynamics).
Explanation:
Explanation:
Thermal Energy refers to the energy within a system that is responsible for it temperature etc.
A scooter maintains a pace of 1.45 minutes per mile, with fuel economy of 85 miles per gallon. How many seconds can it travel on 145 mL of fuel under these conditions
Answer:
281s
Explanation:
Given parameters:
Speed of the scooter = 1.45min per mile
Fuel economy of engine = 85miles per gallon
Quantity of fuel = 145mL
Unknown:
Time of travel with the volume of fuel given = ?
Solution:
To solve this problem, we need to find the distance the fuel will last.
Rate of fuel consumption by the engine = 85miles per gallon
Convert 145mL to gallons;
3785.41mL = 1 gallon
145mL will therefore give [tex]\frac{145}{3785.41}[/tex] = 0.038gallons
So;
Distance covered = 85miles per gallon x 0.038gallons = 3.23miles
From;
Rate of travel = [tex]\frac{time }{distance}[/tex]
Time = rate of travel x distance = 1.45 minutes per mile x 3.23miles
Time = 4.7min
1 min = 60s
4.7min = 4.7 x 60 = 281s
Natural gas is stored in a spherical tank at a temperature of 13°C. At a given initial time, the pressure in the tank is 117 kPa gage, and the atmospheric pressure is 100 kPa absolute. Some time later, after considerably more gas is pumped into the tank, the pressure in the tank is 212 kPa gage, and the temperature is still 13°C. What will be the ratio of the mass of natural gas in the tank when p = 212 kPa gage to that when the pressure was 117 kPa gage?
For this situation in which the tank volume is the same before and after filling, which of the following is the correct relation for the ratio of the mass after filling M2 to that before filling M1 in terms of gas temperatures T1 and T2 and pressures p1 and p2?
a. M2/M1= p2T2/p1T1
b. M2/M1= p1T2/p2T1
c. M2/M1= p2T1/p1T2
d. M2/M1= p1T1/p2T2
1. What is the absolute pressure in the tank before filling?
2. What is the absolute pressure in the tank after filling?
3. What is the ratio of the mass after filling M2 to that before filling M1 for this situation?
Answer:
1. the absolute pressure in the tank before filling = 217 kPa
2. the absolute pressure in the tank after filling = 312 kPa
3. the ratio of the mass after filling M2 to that before filling M1 = 1.44
The correct relation is option c ([tex]\frac{M_{2} }{M_{1} } = \frac{P_{2} T_{1} }{P_{1} T_{2} }[/tex])
Explanation:
To find -
1. What is the absolute pressure in the tank before filling?
2. What is the absolute pressure in the tank after filling?
3. What is the ratio of the mass after filling M2 to that before filling M1 for this situation?
As we know that ,
Absolute pressure = Atmospheric pressure + Gage pressure
So,
Before filling the tank :
Given - Atmospheric pressure = 100 kPa , Gage pressure = 117 kPa
⇒Absolute pressure ( p1 ) = 100 + 117 = 217 kPa
Now,
After filling the tank :
Given - Atmospheric pressure = 100 kPa , Gage pressure = 212 kPa
⇒Absolute pressure (p2) = 100 + 212= 312 kPa
Now,
As given, volume is the same before and after filling,
i.e. [tex]V_{1}[/tex] = [tex]V_{2}[/tex]
As we know that, P ∝ M
⇒ [tex]\frac{p_{1} }{p_{2} } = \frac{m_{1} }{m_{2} }[/tex]
⇒[tex]\frac{m_{2} }{m_{1} } = \frac{p_{2} }{p_{1} }[/tex]
⇒[tex]\frac{m_{2} }{m_{1} } = \frac{312 }{217 } = 1.4378[/tex] ≈ 1.44
Now, as we know that PV = nRT
As V is constant
⇒ P ∝ MT
⇒[tex]\frac{P}{T}[/tex] ∝ M
⇒[tex]\frac{M_{2} }{M_{1} } = \frac{P_{2} T_{1} }{P_{1} T_{2} }[/tex]
So, The correct relation is c option.
What type of charge do ionic compounds have
Answer:neutral
Explanation:ionic compounds is between a cation and anion so they cancel eachother out
Two controlled variables of light?
Answer:
material of the block, the shape of the block and the color of the light
Explanation:
Describe what an alchemist does
How many electrons are in an atom with the electron
configuration of 1s 2s 2p 3s!?
Answer:
11
Explanation:
electronic configuration = 1s^2, 2s^2, 2p^6, 3s^1
therefore total electrons = 2+2+6+1 = 11
Hope it helps youu 。◕‿◕。
How many grams of Ca ( OH )2 , ( Mwt = 74 g / mol ) exists in 2500 mL of 0.0250 M Ca ( OH )2 ?
Answer:
4.6g
Explanation:
We are given the following parameters:
Molecular weight of the compound = 74g/mol
Volume = 2500mL = 2.5L or 2.5dm³
Concentration = 0.025M
Unknown:
Mass of compound = ?
Solution:
To solve this problem, we need to find the number of moles from the given concentration and volume values.
Number of moles = concentration x volume
So;
Number of moles = 0.025 x 2.5 = 0.0625mol
Therefore, mass of compound;
Mass = number of moles x molar mass
Mass = 0.0625 x 74 = 4.6g
The number of I atoms in the reactants is greater than the number in the product : True or False
There are 4 atoms of F in both the reactants and the products. True or False
The illustration represents a valid chemical transformation. True or false
Explanation:
We can summarize the reaction shown as:
2F₂ + I₂ → 2F₃I
Since I is purple
F is the green
The number of I atoms in the reactants is greater than the number in the product
False:
The number of I atoms on both side of the expression is 2
There are 4 atoms of F in both the reactants and the products.
False:
There are 4 atoms of F on the reactant side and 6 atoms of F on the product side
The illustration represents a valid chemical transformation. True or false
False
The reaction does not represent a valid chemical transformation because in a valid chemical transformation, the number of atoms on both sides of the expression must be the same.
Please help!!!! Really need to know this!!
The theoretical yield of NaCl : 15 mol
Further explanationGiven
15 mol Na
15 mol Cl₂
Required
The theoretical yield of NaCl
Solution
Reaction
2Na + Cl₂ ⇒ 2NaCl
A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Find limiting reactant (mol : coefficient) :
Na = 15 : 2 = 7.5
Cl₂ = 15 : 1 = 15
The limiting reactant = Na(smaller ratio)
Mol of NaCl based on mol Na as limiting reactant.
From the equation, mol ratio of Na : NaCl = 2 : 2, so mol NaCl = 15 mol
Use the atomic masses of the elements to determine the percent composition by mass of sodium and chlorine in sodium chloride.
Answer:
Explanation:
Percent composition of sodium chloride .
NaCl
Mol weight = 23 + 35.5 = 58.5 g
58.5 g of NaCl contains 23 g of Na
100 g of NaCl contains 23 x 100 / 58.5 g of Na
= 39.3 %
Na = 39.3 %
58.5 g of NaCl contains 35.5 g of Cl
100 g of NaCl contains 35.5 x 100 / 58.5 g of Na
= 60.7 %
Cl = 60.7 % .
. A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C. a) Write a rate law for the reaction. b) What is the overall order of the reaction
Answer:
a) r = k × [A] × [B]²
b) 3
Explanation:
Let's consider the following generic reaction
A + B + C ⇒ Products
The generic rate law is:
r = k × [A]ᵃ × [B]ᵇ × [C]ⁿ
where
r: reaction ratek: rate constanta, b, n: reaction ordersThis reaction is first order in A, second order in B, and zero order in C. The rate law is:
r = k × [A]¹ × [B]² × [C]⁰
r = k × [A] × [B]²
The overall order of the reaction is the sum of the individual reaction orders.
1 + 2 + 0 = 3