In clinical applications, the unit ppm (parts per million) is used to express very small concentrations of solute, where 1 ppm is equivalent to 1 mg of solute per 1 L of solution. Calculate the concentration in ppm for each of the following solutions.

a) There are 17 ?g calcium in a total volume of 89 mL.
b) There is 0.65 mg caffeine in a total volume of 131 mL.
c) There is 0.35 mg trace particle in a total volume of 91 dL solution.

a. 0.191 ppm b. 4.962 ppm c. 0.0385 ppm

Explanation:

a. 17 g of calcium = 0.017 mg. 89 mL = 0.089 L.

So our concentration = 0.017 mg/0.089 L = 0.191 mg/L = 0.191 ppm

b. 0.65 mg of caffeine in 131 mL = 0.131 L.

So our concentration = 0.65 mg/0.131 L = 4.962 mg/L = 4.962 ppm

c. 0.35 mg of trace particle in 91 dL = 9.1 L.

So our concentration = 0.35 mg/9.1 L = 0.0385 mg/L = 0.0385 ppm

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.