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3 years ago

How many moles of MgCl2 are there in 338 g of the compound

Chemistry

1 answer:

krok68 [10]3 years ago

3 0

atomic mass of magnesium = 24.305

atomic mass of chlorine = 35.453

molecular mass of MgCl2 = 24.305+2*35.453 = 95.211

Number of moles in 338 g of pure MgCl2

= 338/95.211 = 3.55001 moles

Ans. there are 3.55 moles of MgCl2 in 338 g of the substance.

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__________ is the use of high energy radiation to kill cancer cells.

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Answer:

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2 years ago

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How many grams of calcium chloride will be produced when 29.0 g of calcium carbonate is combined with 15.0 g of hydrochloric aci

horsena [70]

Answer:

22.7 g of CaCl₂ are produced in the reaction

Explanation:

This is the reaction:

CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

Now, let's determine the limiting reactant.

Let's divide the mass between the molar mass, to find out moles of each reactant.

29 g / 100.08 g/m = 0.289 of carbonate

15 g / 36.45 g/m = 0.411 of acid

1 mol of carbonate must react with 2 moles of acid

0.289 moles of carbonate will react with the double of moles (0.578)

I only have 0.411 of HCl, so the acid is the limiting reactant.

Ratio is 2:1, so I will produce the half of moles, of salt.

0.411 / 2 = 0.205 moles of CaCl₂

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5 0

4 years ago

Predict the sign of ΔSsys for each of the following processes. Which are positive? (a) Gasoline vapors mix with air in a car eng

OLEGan [10]

Answer:

Positive: a and b

Negative: c

Explanation:

The entropy (S) is the measure of the randomness of the system, and it intends to increase. The randomness can be determined by the energy of the molecules, their velocity and how distance they are between the other molecules.

When the entropy increases, ΔS is positive, when the entropy decreases, ΔS is negative. So, when gasoline mix with air in a car engine, the process intends to continue, the randomness increases and ΔS is positive. When hot air expands, the distance between the molecules increases, so ΔS is positive.

But, when humidity condenses, the molecules stay closer, so there's a decrease in the randomness, then ΔS is negative.

6 0

4 years ago

A solution is prepared from 4.5701 g of magnesium chloride and 43.238 g of water. The vapor pressure of water above this solutio

balandron [24]

Answer:

i = 2.483

Explanation:

The vapour pressure lowering formula is:

Pₐ = Xₐ×P⁰ₐ (1)

For electrolytes:

Pₐ = nH₂O / (nH₂O + inMgCl₂)×P⁰ₐ

Where:

Pₐ is vapor pressure of solution (0.3624atm), nH₂O are moles of water, nMgCl₂ are moles of MgCl₂, i is Van't Hoff Factor, Xₐ is mole fraction of solvent and P⁰ₐ is pressure of pure solvent (0.3804atm)

4.5701g of MgCl₂ are:

4.5701g ₓ (1mol / 95.211g) = 0.048000 moles

43.238g of water are:

43.238g ₓ (1mol / 18.015g) = 2.400 moles

Replacing in (1):

0.3624atm = 2,4mol / (2.4mol + i*0.048mol)×0.3804atm

0.3624atm / 0.3804atm = 2,4mol / (2.4mol + i*0.048mol)

2.4mol + i*0.048mol = 2.4mol / 0.9527

2.4mol + i*0.048mol = 2.5192mol

i*0.048mol = 2.5192mol - 2.4mol

i = 0.1192mol / 0.048mol

i = 2.483

I hope it helps!

4 0

3 years ago

How many liters of a 0.0550 M NaF solution contain 0.163 moles of NaF?

Kobotan [32]

Answer : The volume of solution will be 2.96 liters.

Explanation :

Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.

Formula used :

$\text{Molarity}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

In this question, the solute is NaF.

Now put all the given values in this formula, we get:

$0.0550M=\frac{0.163mole}{\text{Volume of solution (in L)}}$

$\text{Volume of solution (in L)}=\frac{0.163mole}{0.0550M}$

$\text{Volume of solution (in L)}=2.96L$

Therefore, the volume of solution will be 2.96 liters.

3 0

3 years ago