Question

ANSWER THE 3 FOLLOWING QUESTIONS WITH EVIDENCE (40 POINTS):
1. What volume of 0.50M CaCl2 can be produced by dissolving 167.5g of CaCl2?
2. What volume of gas is contained within 13.5mol of gas?
3. What mass of H2 is present in 31.7L of H2 gas?

Answer 1

Answer:

1.  3.02 liters

2. 302.2 liters

3. 2.83 grams

Explanation:

Question 1.

Let's convert the molarity in mass.

Molarity is mol/L, so if we convert the moles to mass, we are talking about a mass, in 1L of solution. (mol . molar mass)

0.5 mol . 110.98 g/m = 55.49 g

Now we can make a rule of three:

If 55.49 grams of chloride are in 1L of solution

then 167.5 g of chloride are in (167.5g . 1L) / 55.49 g = 3.02L

For question 2 and 3, we assume STP, where pressure is 1 atm and T° is 273K. - Standard conditions of temperature and pressure (STP)

Let's apply the Ideal gases law equation

P . V = n . R .T

1 atm . V = 13.5 moles . 0.082 l.atm / mol .K . 273K

V = (13.5 moles . 0.082 l.atm / mol .K . 273K) / 1 atm = 302.2 liters (question 2)

Question 3.

1 atm . 31.7 L = n . 0.082 l.atm / mol.K . 273K

(1 atm . 31.7 L ) / (0.082 l.atm / mol.K . 273K) = 1.41 moles → n

Let's convert moles to mass ( mol . molar mass)

1.41 mol . 2g/mol = 2.83 grams