CHEMISTRY QNS FORM 03
Type keyword | Title of the question to get it easly:
CHEMISTRY | QN 01 | MOLE CONCEPT
15.00g of Aluminium Sulphide and 10.00g water react until the limiting reagent is used up. Here is the balance equation for the reaction.
Al2S3 + 6H2O → Al(OH)3 + 3H2S
a) Which is the limiting reagents?
b) What is the maximum mass of H2S which can be formed from these reagents?
c) How much excess reagents remains after the reaction is complete?
CHEMISTRY | QN 02 | MOLE CONCEPT
If there is 35.0 grams of C6H10 and 45.0 grams of O2, how many grams of the excess reagent will remain after the reaction ceases?
2 C6H10 + 17 O2 → 12 CO2 + 10 H2O
- CHEMISTRY | QN 03 | MOLE CONCEPT
a) What mass of AL2O3 can be produced from the reaction of 10.00g of AL and 19.0g of O3?
b) How much of the excess reagent remains unreacted?
- CHEMISTRY | QN 04 | MOLE CONCEPT
Based on the balanced equation
C4H8 + 6O2 → 4 CO2 + 4 H2O
Calculate the number of excess reagent units remaining when 28 C4H8 molecules and 228 O2 molecules react.
- CHEMISTRY | QN 05 | MOLE CONCEPT
Determine the limiting reagent of this reaction.
Na2B4O7 + H2SO4 + 5H2O → 4H3BO3 + Na2SO4
There are 5.00g of each reactant.
- CHEMISTRY | QN 06 | MOLE CONCEPT
How much O2 could be produced from 2.45g of KO2 and 4.44g of CO2?
4KO2 + 2CO2 → 2K2CO3 + 3O2
- CHEMISTRY | QN 07 | MOLE CONCEPT
a) What mass of hydrogen peroxide should result when 1.45g of barium peroxide is treated with 25.5mL of hydrochloric acid solution containing 0.0277g of HCL per mL?
b) How much of the excess reactant is left?
BaO2(S)+ 2HCL(aq) → H2O(2aq) + BaCL(2aq)
- CHEMISTRY | QN 08 | MOLE CONCEPT
A 2.00g sample 0f ammonia is mixed with 4.00g of Oxygen. Which is the limiting reactant and how much excess reactant remain after the reaction has stopped?
Balanced equation for the reaction:
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(s)
- CHEMISTRY | QN 09 | MOLE CONCEPT
90.0 of FeCL3 react with 52.0g of H2
i. What is the limiting reactant?
ii. What is the mass of HCL produced?
iii. What mass of excess reactant remain after the reaction?
- CHEMISTRY | QN 10 | MOLE CONCEPT
If 120.0g of propane, C3H8 is burned in excess oxygen how many of water are formed.
- CHEMISTRY | QN 11 | MOLE CONCEPT
How many moles of nitrogen are there in a 7.45 mole sample of ammonium phosphate?
- CHEMISTRY | QN 12 | MOLE CONCEPT
How many grams of carbon dioxide are there in a container with a volume of 4.5L at STP?
- CHEMISTRY | QN 13 | MOLE CONCEPT
A sample contains 27.2g of calcium Oxide. How many moles of calcium Oxide are there in the sample?
- CHEMISTRY | QN 14 | MOLE CONCEPT
Take the reaction
NH3 + O2 → NO + H2
In an experiment 325g of NH3 are allowed to read with 3.5g of O2 a) Which reactant is the limiting reagent?
b) How many gram of NO are formed?
c) How much of the excess reactant remain after the reactant?
- CHEMISTRY | QN 15 | MOLE CONCEPT
If 4.95g 0f ethylene (C2H4) are combusted with 3.25g of Oxygen
a) What is the limiting reagent?
b) How many gram of CO2 are formed?
- CHEMISTRY | QN 16 | MOLE CONCEPT
Consider the reaction of C6H2 + Br2 → C6H5Br + HBr
a) What is the liming reagent if 42.1g of C6H6 react with 73.0g of Br2?
- CHEMISTRY | QN 17 | MOLE CONCEPT
A reaction container holds 5.77g of P4 and 5.77g of O2. The following reaction occur
P4 + O2 → P4O6
If there were enough Oxygen were available, then the P4O6 reacts further;
P4O6 + O2 → P4O10
i. Mode of P4O10 produced
ii. Mass of P4O10 produced.
- CHEMISTRY | QN 18 | MOLE CONCEPT
a) Give the meaning of the following terms
i/ Excess reagents
ii/ limiting reagents
b) How to identify the limiting and excess reagent in stoichiometry?
- CHEMISTRY | QN 19 | MOLE CONCEPT
6 mole of nitrogen reacted with 8moles of hydrogen to produce ammonia gas at stp.
i/ limiting reagent
ii/ Excess reagent
b) Calculate the volume of ammonia gas produced at stp by Haber process.
- CHEMISTRY | QN 20 | MOLE CONCEPT
a) Give the meaning of stoichiometry.
b) Outline procedures to be considered when dealing with stoichiometric calculation problems.
c) Mention Procedures to be considered on dealing with excess and limiting reagents problems.
- CHEMISTRY | QN 21 | MOLE CONCEPT
Calculate the volume of oxygen gas product at STP when 12.25g of potassium chlorate are decomposed by heating according to the equation below.
2KCLO3(S) heat→ 2KCL(S) + 302(S)
- CHEMISTRY | QN 22 | MOLE CONCEPT
Ammonium chloride reacts with calcium hydroxide as shown in the following equation.
NH4(aq) + Ca(OH)2(aq) → NH3 + CaCl2(aq) + H2(l)
Calculate the mass of ammonium chloride NH4CI that will read completely with 14.8g of calcium hydroxide.
- CHEMISTRY | QN 23 | MOLE CONCEPT
Sodium sulphate react with barium nitrate as shown in the equation below.
Na2SO4(aq) + Ba (NO3)2(aq)→BaSO4s + 2NaNO2(aq)
How many moles of barium Sulphate are produced when 80.5g of Sodium Sulphate react completely with barium nitrate?
- CHEMISTRY | QN 24 | MOLE CONCEPT
4.90g of copper (II) Oxide yielded 3.92g of copper when reduced by hydrogen gas.
Calculate the mass of copper (II) oxide required to yield 4g of copper. (Cu=64, O=16)
- CHEMISTRY | QN 25 | MOLE CONCEPT
The decomposition of Pb(NO3)2 is as shown below.
Pb(NO3)2(S)→2PbO(S) + 4NO2(g) + O2(g)
If 0.01 mole of the nitrate was used, what would be the maximum volume of oxygen gas collected at room temperature and pressure?
(molar gas volume at rtp = 24.0 cm33)
- CHEMISTRY | QN 26 | MOLE CONCEPT
What mass of anhydrous Sodium Carbonate would be required to completely react with 20cm3 of 0.4M Sulphuric acid solution.
(Na = 23, 0 = 16, C = 12, H = 1)
- CHEMISTRY | QN 27 | MOLE CONCEPT
1.63g of Zinc metal was added to excess Silver Nitrate Solution. The mass of silver formed was 5.40g.
(Zn = 65, Ag = 108)
What is the equation for the displacement reaction?
Show the working.
- CHEMISTRY | QN 28 | MOLE CONCEPT
100 cm3 of 1M NaOH was mixed with 100 cm3 of 0.1M HCI.
After the reaction.
a. Which ions were in excess and by how much?
b. Find the concentration of the excess ions.
- CHEMISTRY | QN 29 | MOLE CONCEPT
Lead nitrate decomposes on heating as shown in the equation below.
Pb (NO3)2 heat → 2PbO(S) + 4N02(S) + O2(g)
112dm3 of oxygen gas were collected at STP when a sample of lead nitrate was completely decomposed by heating. Calculate;
a. The mass of the lead nitrate sample.
b. The mass of lead (II) oxide produced.
c. The volume of nitrogen dioxide gas produced at STP.
(Pb = 207, Na =14, 0 = 16; molar volume of a gas at STP = 22.4 dm3)
- CHEMISTRY | QN 30 | MOLE CONCEPT
The equation below shows the reaction the reaction between heated copper (II) oxide and ammonia gas.
3CuO(g) + 2 NH3(g) → 3Cu(S) + N2(g) + 3H2O(l)
If 20g of copper (II) oxide reacted with ammonia gas at STP.
a. The number of moles of copper (II) oxide used.
b. The volume of ammonia gas used.
c. The mass of copper formed.
(Cu = 64, 0 = 16, N = 14, H = 1. Molar volume of a gas at STP = 22.4 dm3)