chemistry check in ch 3.2 and 3.3
light travels at a speed of 3.00 x 10^10 cm/s. what is the speed of light in kilometers/hour?
1.08 x 10^9 km/h
a weather ballon is inflated to a volume of 2.2 x 10^3 L with 374 g of helium. what is the density of helium. What is the density of helium in grams per liter?
37.4 g/2.2 x 10^3L = 0.017 grams per liter
Why are metric units easy to use?
All metric units are based on multiples of 10. As a result, you can convert between units easily.
What determines the density of a substance?
Density is an intensive property that depends only on the composition of a substance, not on the size of the sample.
What temperature units do scientists commonly use?
Scientists commonly use two equivalent units of temperature, the degree Celsius and the kelvin.
how does density vary with temperature?
The density of a substance generally decreases as its temperature increases.
make the following conversions. express your answer in scientific notation.
a. 14.8g x 10^7IUg. d. 7.5 x 10^1 KJ b. 3.72 x 10^-3 kg. e. 3.9 x 10^3 dg c. 6.63 x 10^4 cm^3. f. 2.21 x 10^1 IuL
what conversion factor would you use to convert between these pairs of units?
a. minutes to hours - 1hr/60minutes b. grams to miligrams - 10^3mg/ug c. cubic decimeters to millimeters - 10^3mL/1dm^3
what is the mass, in kilograms, of 14.0 L of gasoline? (Assume that the density of gasoline is 0.680 g/cm^3)
d = m/v m = dv
Write the symbol and the meaning of each prefix: milli- , nano- , deci- , centi-
deci (d): 10 times smaller than the unit it precedes centi (c): 100 times smaller than the unit it precedes milli (m): 1000 times smaller than the unit it precedes nano (n): 1 billion times smaller than the unit it precede
What types of problems can be solved using dimensional analysis?
dimensional analysis is a powerful tool for solving conversion problems in which a measurement with one unit is changed to an equivalent measurement with another unit
surgical instruments may be sterilized by heating at 170 degrees c for 1.5 hour convert 170 degrees celsius to kelvins.
k = c + 273
look up the densities of the elements in group 1A on page R2. which group 1A elements are less dense than pure water at 4 degrees c?
lithium, sodium, potassium
arrange the following units in order from largest to smallest: m^3, mL, cL, IUL, L, dL,
m^3, L, dL, cL, mL, uL
Write the name and symbol of the SI units for mass, length, volume, and temperature?
mass: kilogram (kg) length: meter (m) volume: cubic meter (m^3) temperature: kelvin (k)
a 68-g bar of gold is cult into three equal pieces. how does the density of each piece compare to the density of the original gold bar?
they have the same density because density depends on the composition of a substance, not on the size of the sample
What is the volume of a paperback book 21 cm tall, 12 cm wide, and 3.5 cm thick?
volume = 21 x 12 x 3.5 = 882cm
state the difference between mass and weight
weight, a measure of force, is different from mass which is a measure of the quantity of matter
what happens to the numerical value of a measurement that is multiplied by a conversion factor? what happens to the actual size of the quantity?
when a measurement is multiplied by a conversion factor, the numerical value is generally changed, but the actual size of the quantity measured remains the same