PART A Theobromine C7H8N4O2 is a component of chocolate It i

PART A) Theobromine, C₇H₈N₄O₂, is a component of chocolate. It is mildly diuretic, is a mild stimulant, and relaxes the smooth muscles of the bronchi in the lungs. Because dogs metabolize it more slowly than humans, theobromine is very toxic to dogs.

If there are 0.064 g of theobromine in a 43 g chocolate bar, how many moles of theobromine are there?

a) 1.5 x 10³ moles

b) 3.55181 x 10⁴ moles

c) 3.6 x 10⁴ moles

d) 12 moles

PART B) Calculate the molarity (M) of 151.1 g of H2SO4 in 1.405 L of solution.

Express your answer to four significant figures.

part c) Sodium hydroxide, NaOH, is a strong base that is used in industrial synthesis and processes such as making paper.

What is the mass of 2.30 ×1022 molecules of NaOH (Molar mass = 40.0 g/mol)?

Express the mass in grams to three significant figures.

Solution

part A)

Molar mass of theobromine = 180.16 g/mol

mass = 0.064 g

moles = mass / moalr mass

          = 0.064 / 180.16

moles = 3.55 x 10^-4 mol

Answer : c) 3.6 x 10⁴ moles

Part B)

moles of H2SO4 = 151.1 / 98 = 1.542 mol

Molarity = moles / volume = 1.542 / 1.405

Molarity = 1.097 M

part C)

moles of NaOH = 2.30 x 10^22 / 6.023 x 10^23

                         = 0.0382 mol

mass of NaOH = 1.53 g