Chemistry Assignment Guruh Worksheet

ENGR 1540 Worksheet 9 Chapter 3

1. A large family of boron-hydrogen compounds has the general formula BxHy. One member of this family contains 88.5% B; the remainder is hydrogen. What is its empirical formula?

2. Mandelic acid is an organic acid composed of carbon (63.15%), hydrogen (5.30%), and oxygen (31.55%). Its molar mass is 152.14 g/mol. Determine the empirical and molecular formulas of the acid.

3. Determine the simplest formulas of the following compounds.
a. the food enhancer monosodium glutamate (MSG), which has the composition 35.51% C, 4.77% H, 37.85% O, 8.29% N, and 13.60% Na
b. zircon, a diamond-like mineral, which has the composition 34.91% O, 15.32% Si, and 49.76% Zr
c. nicotine, which has the composition 74.0% C, 8.65% H, and 17.4% N

4. Calculate the molarity of each of the following solutions.
a. 1.45 mol HCl in 250. mL of solution
b. 14.3 mol NaOH in 3.4 L of solution
c. 0.341 mol KCl in 100.0 mL of solution
d. 250 mol NaNO3 in 350 L of solution

5. What is the molarity of each ion present in aqueous solutions prepared by dissolving 20.00 g of the following compounds in water to make 4.50 L of solution?
a. cobalt(III) chloride
b. nickel(III) sulfate
c. sodium permanganate
d. iron(II) bromide

6. How many moles of solute are present in each of these solutions?
a. 48.0 mL 0f 3.4 M H2SO4
b. 1.43 mL of 5.8 M KNO3
c. 3.21 L of 0.034 M NH3
d. 1.9×103 L of 1.4×10-5 M NaF

7. How many grams of solute are present in each of these solutions?
a. 37.2 mL of 0.471 M HBr
b. 113.0 L of 1.43 M Na2CO3
c. 21.2 mL of 6.8 M CH3COOH
d. 1.3×10-4 L of 1.03 M H2SO3

8. Determine the final molarity for the following dilutions.
a. 24.5 mL of 3.0 M solution diluted to 100.0 mL
b. 15.3 mL of 4.22 M solution diluted to 1.00 L
c. 1.45 mL of 0.034 M solution diluted to 10.0 mL
d. 2.35 L of 12.5 M solution diluted to 100.0 L

9. Determine the initial volume (in mL) needed to generate each of the following desired solutions by dilution.
a. 10.0 L of 0.45 M solution from 3.0 M solution
b. 1.50 L of 1.00 M solution from 11.7 M solution
c. 100.0 mL of 0.025 M solution from 1.15 M solution
d. 50.0 mL of 3.3×10-4 M solution from 0.25 M solution

10. Commercially available concentrated sulfuric acid is 18.0 M H2SO4. Calculate the volume of concentrated sulfuric acid required to prepare 2.50 L of 1.50 M H2SO4 solution.