CHEM

moles to atoms

moles given x 6.02 x 10^23 molecules / 1 mol x # atoms in compound / 1 molecule = ____atoms

Calculate moles to particles

moles given x 6.02 x 10^23/1 mol = ___________particles

particles to grams

particles given x 1mol/6.02 x 10^23 x molar mass/1 mol = _______grams

from particles to moles

particles given x 1mol/6.02 x 10^23= ____________moles

Calculate to Grams

Moles given x molar mass/1 mol = ____________g

Empirical formula

1. change g or % to moles 2. divide each mole by smallest number of the moles 3. write formula using whole number ratios

The temperature reading of -14C corresponds to Kevin as :

259 k

Molar Mass

(atomic mass from periodic table) (number of atoms) Add them together and label in g

percent composition

(must find molar mass of compound) take each element's mass in g or % divided by the compounds molar mass then multiply by 100 (to make a %) (if given masses divide each compounds mass by total mass and round answers for sd)

Chlorine boils at 239 K. what is the boiling point of chlorine expressed in degrees Celsius

-34 C

Find the mass in kg of 6.25 mol of sulfuric acid

0.613 kgH2SO4

1000mL =

1 L

volume formulas

1) moles given x 22.7/1 mol = dm^3 2) dm^3 given x 1 mol / 22.7 = moles 3) density: molar mass g / 1 mol x 1 mol / 22.7 dm^3 = gdm^-3 4) molar mass: density g / dm^3 x 22.7 / 1mol = gmol^-1

Molecular formula

1. find empirical formula 2. find molar mass of empirical formula 3. divide molar mass given in problem by molar mass of empirical formula (whole number) 4. multiply each let in empirical formula by the whole number found in #3 5. write formula

what is the mass in grams of 3.75 x 10^15 atoms of gold

1.23 x 10^-6 g Au

What does the metric prefix kilo mean

1000 times larger

1dm^3 =

1000mL

148.576g - 35.41g

113.17 (113.2) g

Calculate the percent of magnesium in magnesium nitrate

16.39%

if 0.25 moles of a substance has 48g what is the molar mass of the substance

192 gmol^-1

1000cm^3 =

1dm^3

(5.6 x 10^7 m) (3.60 x 10^-2 m)

2.0 x 10^6 m^2

(8.74 X 10^9M^2)/(4.22x10^-6m)

2.07 x 10^15 m

Concentrated hydrochloric acid has a density of 1.19 g/ml. What is the mass in grams of 2.00 liters of this acid

2.38 x 10^3 g

How many milligrams are in 2.5 kg

2.5 x 10^6 mg

Convert -55.2C to K

218k

Write the expression that represents the percent error for NH4NO3

28.0 G / 80.0 G X 100

How many sig figs? 7.30 x 10^-7

3

How many atoms are in 0.25 mol of iron(II)sulfide

3.0 x 10^23 atoms FeS

What is the volume in cm^3 of 1.5mol of carbon dioxide at STP

3.4 x 10^4 cm^3 CO^2

The molar mass of molecular oxygen is :

32.0 g

The chemical formula of aspirin is C9H8O4. What is the mass of .200 mol of aspirin?

36.0g

How many moles of SO3 are in 2.4 x 10^24 molecules of SO3

4.0

How many moles are in 2.77 x 10^24 molecules of carbon monoxide?

4.60 mol CO

How could you calculate a 40 hours work week

40h x 60min/1 h x 60s/1 min

what is the concentration of 250.0 cm ^3 of 1.3 moles of sodium chloride

5.2 mol dm^-3

36.47cm + 2.721cm + 15.1cm

54.3 cm

What is the volume (in liters at STP) of 2.50 mol of carbon monoxide?

56.0 L

What is the percent error of carbon in acetone, C3H60

62%

A large weather ballon filled with helium has a volume of 7.00 x 10^2 L at STP. What should be used to find the mass of the ballon

7.00 x 10^2 L/22.4 L/mol x 4 g He/mol

what is the mass in g of 300.0cm^3 of 0.300 mol dm^-3 sodium hydrogen carbonate

7.56 g Na HCO3

43.7 mmin^-1 to cms^-1

72.8 cms^-1

A student measures a volume as 25 ml whereas the correct volume is 23 ml. What is the percent error?

8.7%

What is the volume of 60.0g of ether if the density of ether is 0.70 g/ml

86 ml

the empirical formula of a compound is C2H3O and has a molar mass of 172g/mol. what is its molecular formula

C8H12O4

what is the empirical formula of a compound that is 27.3% carbon and 72.7% oxygen

CO2

Give an example of a non empirical formula

N2H4

What is the metric unit of volume

L

A compound consisting of 56.38% phosphorus and 43.62% oxygen has a molar mass of 219.9 g/mol. determine the molecular formula

P4O6

The closeness of a measurement to its true value is a measure of its:

accuracy

Calculate to moles

grams given x 1 mol/ molar mass = ___________mol

grams to particles

grams given x 1mol/molar mass x 6.02 x10^23 /1 mol = _______particles

At STP, 1 mol each of hydrogen, oxygen, nitrogen, and fluorine:

have different densities

Find the percent composition of a compound containing sulfur and fluorine if a 19.75g sample contains 5.88g of sulfur

s= 29.8% F= 70.23%

The molar mass of a gas can be determined by

the density of the gas at STP