Practice Problems
Write a balanced reaction for the combustion of sucrose (C12H24O11)?
2(C12H24O12) + 25(O2) -----> 24(CO2) + 24(H2O)
how many moles are present in 33.7 grams of HCl
4.37
Find the molar mass of C3H8
44.094
Find the molar mass of C19H19N7O6
441.412
How many atoms of carbon are in 1.5 carat diamond if one carat equals 200mg of carbon?
1.504 x 10^22 atoms Carbon 1.5x 200mg x g/1000 x MM(m/g) x 6.02x10^23molecules/m= Molar Mass= C= 12.011g/mole
How many molecules of water are in a 500 mL *Density of H2O: 1g = 1mL
1.6716 x 10^25 molecules 500mL x g/ml x MM(m/g) x 6.02 x 10^23 molecules/m= Molar Mass= 18.016g/m H= 2.016 O= 16.00
what is the pH of a solution prepared by mixing 200grams of water with .13 grams of HCl
1.75
How many Hydrogen atoms are in 25 grams of glucose (C6H12O6)?
10.03 x 10^23 atoms of Hydrogen 25g x MM(m/g) x 12 mH/m x 6.02 x 10^23Hatom/mH= Molar Mass= 180.196g/mole C= 72.066 H= 12.096 O= 96
Find the molar mass of Al2O3
101.96
if a 50mL sample of ocean water contains .0056 grams of magnesium (Mg), what is the ppm concentration of magnesium? Assume the density of ocean water is 1g/mL
112
what is the pH of a solution prepared by mixing 200 grams of water with .13 grams of NaOH?
12.21
Find the molar mass of C6H8O6
176.124
provide the balanced equation for the combustion of propanol (C3H8O) and include all the reaction products
2(C3H8O) + 9(O2) -----> 6(CO2) + 8(H2O) + heat + light
Write a balanced reaction for the combustion of butane (C4H10)?
2(C4H10) + 13(O2) -----> 8(CO2) + 10(H2O)
Write a balanced reaction for the combustion of benzene (C6H6)?
2(C6H6) + 15(O2) -----> 12(CO2) + 6(H2O)
If a mixture is prepared by dissolving 28.5 grams of glucose (C6H12O6) in 100 mL of water, what is the percent glucose in this solution?
22.18
Find the molar mass of HCl
36.458
How many moles of CO2 are produced with the combustion of 56.9 grams of C6H6? How many moles of O2 are consumed? How many grams of water are produced?
39.373
Find the molar mass of NaOH
39.998
if the concentration of hydroxide (OH-) is 2.5x10^-5 M in a sample of water, what is the molar concentration of hydronium ion (H3O+)? What is the pH of the solution?
4 x 10^-10 9.4
How many Carbon atoms are in 25 grams of glucose (C6H12O6)?
5.01 x 10^23 atoms of Carbon 25g x MM(m/g) x 6mC/m x 6.02 x 10^23 Catoms/mC = Molar Mass= 180.196 g/mole C= 72.066 H= 12.096 O= 96
How many grams of NaOH are needed to obtain .003 moles
5.46
What is the parts per million (ppm) concentration of nitrate in a sample of water of 0.0137 grams of nitrate are determined to be in 2.00 liters of this sample?
6.85ppm 0.0137g/2L x L/1000mL x mL/g x 1million =
What is the molar mass for benzene (C6H6)
78.1134grams/mole
How many molecules are in 25 grams of glucose (C6H12O6)?
8.3537 x 10^23 Molecules 25g x MM(m/g) x 6.02 x 10^23 molcules/g= molecules Molar Mass= 180.196g/mole C= 72.066 H= 12.096 O= 96
How many grams of sodium chloride (NaCl) must be weighed to obtain 1.5 moles
87.66
Silver sulfide (Ag2S) dissolves in water to form silver ions (Ag+) and sulfide ions (S-) Write a balanced equation for this reaction write its equilibrium expression
Ag2S -----> 2(Ag+) +S- Keq= {[Ag^2] x S} / (Ag2S)
Ammonia reacts with water via the following reaction write the equilibrium expression for this reaction is ammonia an acid or a base?
NH3(aq) + H2O <=====> NH4(aq)+ + OH-(ag) Keg = {(NH4) x (OH)} / (NH3) It is a base because of (OH-)
Find the molar mass of SnClBr2
313.95
How many grams of sodium chloride must be added to 250 ml of water to create a solution that has a concentration of 0.0516 M?
.7539g concentration x L/ml x 250 ml x MM(g/m) Molar Mass= 58.44g/m Sodium=22.99 Chloride= 35.45
Write the equilibrium expression for the combustion of butane (C4H10):
Keq= {[(CO2)^8] x [(H2O)^10]} / {[(C4H10)^2] x [(O2)^13]} Balanced Equation: 2(C4H10) + 13(O2) -----> 8(CO2) + 10(H2O)
If a sample of river water has a concentration of 13 ppm nitrate (NO3-), how many grams of nitrate are present in 100 grams of this river water?
.0013
How many grams of NaOH must be added to 1 liter of water to produce a solution with a pH of 10?
.004
What is the molar concentration of potassium nitrate (KNO3) in a solution prepared by adding 3.28 grams of KNO3 to one liter of water?
.03233 molar (m/L) 3.28g x MM(m/g)= moles L + (3.28g x ml/g x L/1000mL) = L
How many moles of HCl must be added to water to generate a solution with .0823 molar concentration of chloride ions (Cl-)?
.04115
What is the molar concentration of hydroxide [OH-] when 3.56 grams of NaOH is dissolved in 100ml of water
.8899 M (moles/liter)
how many grams of sucrose (C12H22O11) must be added to 200mL of water to produce a solution that is 2.3% sucrose?
4.708
Find the molar mass of MgOH2
42.326
Write a balanced reaction for the combustion of heptane (C7H16)?
C7H16 + 11(O2) -----> 7(CO2) + 8(H2O)