# Chemistry Assignment 2

Convert the following numbers from scientific notation to standard notation:

.28 X 10³= 280

.84 X 10⁻⁵= .0000184

.205 X 10⁻² =.00205

.37 X 10⁴ =3700

Carry out the following conversions.

a. 56.4 mi to kilometers and to mega meters.

$.56 miles =56.4*1.609 =90.7476 Km =0.09 Mm$

b. 2.0 L to quarts and to fluid ounces.

$L = 2*1.056 quarts =2.112 quarts$

$L =2*33.814 oz = 67.628 oz$

c. 7ft 2.0 in. to centimeters and to meters.

$7ft 2in =7*30.5 +2*2.54 =218.58 cm =2.186 m$

d. 135 lb to kilograms and to decigrams.

$135 lb =135*0.454 = 61.29 kg =612.29 decigrams$

Which SI unit prefix corresponds to each of the following multipliers?

a. 10³

kilo

b. 10⁻³

mili

c. 10⁶

mega

d. 10⁻⁶

micro

The muzzle velocity of a projectile fired from a 9mm handgun is 1200ft/s.

a. How many miles per hour is this?

$1200 ft/s = 1200*0.000189*3600 miles/hour = 816.48 miles/h$

b. How many meters per second?

$1200 ft/s =1200*0.3 m/s = 360 m/s$

The boiling point of liquid nitrogen, used in the removal of warts and in other surgical applications, is -195.8˚C. What is this temperature in kelvins and in degrees Fahrenheit?

$-195.8 Celsius =-195.8+273 = 77.2 K = -195.8*9/5 +32 Fahrenheit = 320.44 Fahrenheit$

Copper has a specific heat of 0.092cal/(g.˚C). When 52.7 cal of heat is added to a piece of copper, the temperature increases from 22.4˚C to 38.6˚C. What is the mass of the piece of copper? (convert to Kelvins only).

mass *(temperature variation)*specific heat = Total heat

$mass =52.7/0.092/(38.6-22.4) =35.36$ g

You do not need to convert to Kelvin as the temperature variation is the same in the Celsius and Kelvin scales

What is the density of lithium metal (in g/cm³) If a cube measuring 0.82 cm X 1.45 cm X 1.25 cm has a mass of 0.794g?

$Volume =0.82*1.45*1.25 =1.48625 cm^3$

$density =0.794/1.48625 = 0.534 g/cm^3$