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Sig Figs
Moles
Molarity
Dilutions
100

When do trailing zeros count towards significant figures?

Only when there is a decimal present.

100

What is Avogadro's number? Give the entire conversion rate.

6.02 x1023 particles = 1 mole

100

What does molarity measure?

moles of solute per volume of solution

concentration

100

What is the dilution equation? What does each variable represent?

C1V1 = C2V2

C1 = stock solution conc, V1 = volume stock solution, C2 = diluted solution conc, V2 = final volume diluted solution

200

What are the number of significant figures in the number 0.004 302 890?

7

200

There are 4.948 x1025 molecules of O2 in a balloon. How many moles of O2 is this?

82.19 moles

200

What is the molarity of a solution with 3.98 moles NaCl in 1.473 L of water? 

2.70 M

200

You have 50.0 ml of your 1.35 M stock solution. You want to dilute this to 125.0 ml. What is the final concentration? 

0.54 M 

300

What is the correct answer with the correct significant figures?

0.100 427 x 15,000. / 279.305 = 

5.3934 

300

How many grams is 1 mole of calcium?

40.078 g

300

How many moles of potassium nitride do you have in 156.4 ml of a 0.25 M solution? 

0.039 moles 

300
You begin with 14.8 ml of a 3.5 M solution. You add 50.0 ml of water. What is the final concentration?

0.80 M

400

A graduated cylinder measures every 1 ml. How many significant figures would 10 ml have using this tool?

3 sig figs

10.0

400

How many molecules of calcium bromide are in 3.52 grams? 

1.06 x1022 molecules

400

What is the molarity of a solution of 27.4 grams of strontium sulfide in 244.7 ml of water?

0.505 M

400

You have 43.7 ml of a 1.56 M solution and dilute it to 0.89 M. How many ml of water did you add to the solution?

33 ml of water

500

What is the correct answer with the correct significant figures?

4.2907 x 190.2 / 0.000 015 * 0.000 7 / 102,000. = 

0.4 

500

How many atoms of carbon are in 4.7 grams of C8H10?

2.1 x1023 atoms of C

500

A solution has 2.64 x1022 molecules of C12H22O11 in 50.0 ml of water. If you wanted to make 250.0 ml of this solution, how many grams of C12H22O11 would you need to weigh out?

75.1 grams

500

You make 500.0 ml of a 5.6 M stock solution. You want to make 100.0 ml of a 1.35 M solution. How would you make this in the lab?

Add 24 ml stock solution and 76 ml of water.