Question 1

Given the expression $$\frac{6.2 	imes 10^4$}{3.1 	imes 10$$^{-2}$$}$$, what is the result expressed in scientific notation?

Accepted Answer

$$2.0 	imes 10^7$

Question 2

Which of the following is the correct result for $$\frac{4.8 	imes 10$$^{-3}$$}{6.0 	imes 10^2$} in $$scientific notation?

Accepted Answer

$$8.0 	imes 10$$^{-5}$$

Question 3

A student calculates $$\frac{7.2 	imes 10^5$}{8.0 	imes 10$$^{-3}$$}. $$What is the answer in scientific notation?

Accepted Answer

$$9.0 	imes 10^7$

Question 4

If you divide $$5.0 	imes 10$$^{-6}$$ by 2.5$$ 	imes $$10^3$$, what is the result in scientific notation?

Accepted Answer

$$2.0 	imes 10$$^{-9}$$

Question 5

Which of the following is the correct result for $$\frac{9.0 	imes 10^2$}{3.0 	imes 10$$^{-4}$$}$$?

Accepted Answer

$$3.0 	imes 10^6$

Question 6

A laboratory sample has a mass of $$2.4 	imes 10$$^{-2}$$ grams and a volume of 8.0$$ 	imes $$10^{-3}$$ liters. What is the density in $$g/L$$?

Accepted Answer

$$3.0 	imes 10^0$

Question 7

A chemical reaction produces $$1.2 	imes 10^3$ molecules per second. How many molecules are produced in 2.5$$ 	imes $$10^2$$ seconds?

Accepted Answer

$$3.0 	imes 10^5$

Question 8

If a solution contains $$4.5 	imes 10$$^{-5}$$ moles of solute in 9.0$$ 	imes $$10^{-2}$$ liters, what is the molarity?

Accepted Answer

$$5.0 	imes 10$$^{-4}$$\ M$

Question 9

A reaction vessel contains $$6.0 	imes 10^2$ grams of a substance. If the molar mass is 3.0$$ 	imes $$10^1 g/$$mol, how many moles are present?

Accepted Answer

$$2.0 	imes 10^1$\ mol

Question 10

A medication is administered at a rate of $$2.0 	imes 10$$^{-1}$$ mg/min for 5.0$$ 	imes $$10^2$$ minutes. What is the total mass of medication delivered?

Accepted Answer

$$1.0 	imes 10^2$\ mg

Question 11

A scientist needs to dilute a $$1.0 	imes 10^1$ M solution to 2.0$$ 	imes $$10^0 M. If $$she starts with $$5.0 	imes 10$$^{-1}$$ L of the concentrated solution, what will be the final volume after dilution?

Accepted Answer

$$2.5 	imes 10^0$\ L

Question 12

A radioactive isotope decays at a rate of $$3.0 	imes 10^4$ atoms per hour. How many atoms will decay in 4.0$$ 	imes $$10^2$$ hours?

Accepted Answer

$$1.2 	imes 10^7$

Question 13

A solution is prepared by dissolving $$3.0 	imes 10$$^{-2}$$ moles of NaCl in 6.0$$ 	imes $$10^{-1}$$ liters of water. What is the molarity of the solution?

Accepted Answer

$$5.0 	imes 10$$^{-2}$$\ M$

Question 14

A chemist needs $$2.0 	imes 10^2$ mL of a 1.0$$ 	imes $$10^{-1} M $$solution. How many moles of solute are required?

Accepted Answer

$$2.0 	imes 10$$^{-2}$$\ mol

Question 15

A patient receives an IV drip at a rate of $$4.0 	imes 10$$^{-2}$$ L/hr for 2.5$$ 	imes $$10^1$$ hours. What is the total volume administered?

Accepted Answer

$$1.0 	imes 10^0$\ L

Scientific Notation and Significant Figures in Chemistry Calculations

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