1. Carry out the following operations, and express the answer with the appropriate number of significant figures and units:

a. (5,23 mm)(6.1 mm) =

b. 72.3 g/1.5 mL =

c. 12.12 g + 0.0132 g =

d. 31.03 g + 12 mg =

2. Drug medications are often prescribed on the basis of body weight. The adult dosage of Elixophyllin, a drug used to treat asthma, is 6 mg/kg of body mass. Calculate the dose in milligrams foe a 150-lb person?

3. A pipet delivers 9.98 g of water at 20 °C. What volume does the pipet delivers?

4. A141-mg sample was placed on a watch glass that weighed 9.203 g. What is weight of the watch glass and sample in grams>