# Chemistry #2

### 17 terms by mcostakis

#### Study  only

Flashcards Flashcards

Scatter Scatter

Scatter Scatter

## Create a new folder

chemistry #2

### significant figures

the digits in the measurement that are known with certainty plus one digit that is uncertain
#Sig. fig. = all certain numbers + one uncertain number

those at the beginning of a number are NEVER significant.
ex. 0.00035 has 2 sign. #

### confined zeros

those between nonzero digits are ALWAYS significant
ex. 3.0689 has 5 significant figures

### Trailing zeros

those at the end of the a number, are significant only if a decimal point is present in the number.
35.00 has four sig.fig.
0.05060 has four sig.fig.
86,000. has 5 sig.fig.

### Trailing zeros (no decimal point)

are not significant if the number lacks a decimal point.
6,000,000 has one sig. fig.
70050 has four sig. fig.

### Significant figure: multiplication and division

- is the same as the number of significant figures in the measurement that contains the fewest significant figures.
- In multiplication and division significant figures are counted.

### Significant figure:

- the answer has no more digits to the right of the decimal point than are found in the measurement with the fewest digits to the right of the decimal point.
- In addition and subtraction, decimal places are counted.

### scientific notation

- With scientific notation...only significant figures appear in the coefficient.
Ex. 86 ---> 2 Sig. Figs. ----> 8.6 x 10¹
Ex. 86.0 --->3 sig. figs. ---->8.60 x10¹

### density

the ratio of the mass of an object to the volume occupied by that object

density = mass/volume

K = C =273
C = K - 273

F = 9/5(C) + 32
C = 5/9(F -32)

### calorie

the amount of heat energy needed to raise the temperature of 1 gram of water by 1 degree celsius

### kilocalorie

1 kilocalorie = 1000 calories

### joules

1 calorie = 4.184 joules

### specific heat

the quantity of heat energy, in calories, necessary to raise the temperature of 1 gram of a substance by 1 degree celsius.

### heat absorbed

= specific heat X mass X temperature change

### volume

length X width X height

Example: