Chemistry Midterm Review

Keeping in mind rounding and significant figures, what s 64/30/15?

0.1

Keeping in mind the rules for significant digits, subtract 7.33 cm from 8.5 cm.

1.2 cm

What is the proper solution to the following equation? (27.9 / 4.0) - 7.6134 + 11.431 =

10.8

What is 0.00397 in scientific notation?

3.97 x 10^-3

What is the answer with proper significant figures for the following equation? (7.6 + 8.401) x 4.2 x 0.688

46

How many significant digits are found in 765.000?

6

The quantity 0.0000064 g expressed in scientific notation is

6.4 x 10^-6 g

Keeping in mind scientific notation, rounding, and significant figures, what is 29 x 20?

600 EXPLANATION: for multiplying/dividing, the answer contains the least # of sigfigs. 20 only has 1 sigfig, as well as 600, therefore you round the answer up/down to the closest # with only 1 sigfig.

The number 8.314 written in scientific notation becomes

8.314 x 10^0

What is 0.00875 in scientific notation?

8.75 x 10^-3

Calculate the quantity 87.3 cm - 1.728 cm

85.6 cm

Which of the following is a chemical change?

A liquid evaporates.

Which of the following is a chemical change?

Sulfur dioxide is formed when sulfur combines with oxygen.

One afternoon, a man painted his house brown. Two days later, however, the house caught on fire and burned down. What two changes occurred to the house?

The painting was a physical change and the burning was a chemical change.

You bought a 5 pound bag of sugar at HEB. Not trusting the store, you weighed the sugar at home to make sure that you got what you paid for. Your scale reports that the store's 5 pound bag of sugar does weigh 5 pounds. This is an example of

accuracy

________ refers to how closely a measured value agrees with the correct value.

accuracy

Elements can be distinguished by their

density.

The number 2 x 10^15 is

greater than one.

You have a reported 1 pound bar of gold, but every time you weigh it, the scale reports that t weighs 937.00 g. This is an example of

precision

________ refers to how closely individual measurements agree with each other.

precision

Which of these processes is a chemical change, NOT a physical change?

the burning of a match

The major importance of significant figures is

to show the degree of uncertainty or precision in measurements.

If you were to hammer some gold into a thin sheet, the atoms

would be unchanged.