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When copper sulphate is dissolved in water in a beaker, a bright blue liquid or solution is formed. If copper sulphate is added until no more will dissolve, a saturated solution is formed. Some blue crystals will remain at the bottom of the beaker. What was the solvent used?
if a sample of caproic acid was found to have 0.140 g carbon, 0.0234 g hydrogen and 0.0622 g of oxygen, what is its empirical formula? if the molar mass of the caproic acid is 116 g/mol, what is it molecular formula
how many moles of sodium oxide are produced if 0.5 mol of Fe is produced in the reaction 6Na + Fe2O3 3Na2O + 2Fe
A fertilizer advertised as 8-8-8 generally means it contains 8% total nitrogen, 8% P2O5, and 8% K2O.
Calculate the percentage of P and K in the fertilizer
A cuvette with a path length of 1.2 cm and solution containing 0.86 mol/dm3
of a dye
gives an absorbance of 0.8. Calculate the molar extinction coefficient of the dye.
4. In testing for the effectiveness of an antacid compound, 5.0 g hydrochloric acid is mixed with magnesium hydroxide.
a..Write a balanced equation for the reaction. /3
b.Determine the number of moles of magnesium hydroxide required to react with the acid /3
c. If there is 24.0 g magnesium hydroxide in the lab, determine if it will be enough to react with acid. /3
5. While practising stoichiometric calculations, a classmate asks you to check his work. Help your classmate by correcting his solution below; make sure to check for correct mathematical format and calculations. Circle the errors and write the corrections beside them. /3
7.A mineral found in a mine site near Bancroft, ON is identified as “Barite”. A geochemist’s analysis finds that it consists of 21.93% barium, 5.12% sulfur and 10.24% oxygen. (7 marks)
a.Determine the empirical formula
b.Further analysis of the mineral determined the molecular mass of the compound to actually be, M°MF = 233.40 g/mol. Find the molecular formula for this compound.
8.What is the mole ratio for lithium hydroxide to hydrogen gas in the following reaction?
2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g) (1mark)
9.Aluminum carbide, Al4C3(s), is a yellow powder that reacts with water, H2O(ℓ), to produce aluminum hydroxide, Al(OH)3(s), and methane, CH4(g).
- Write a balanced chemical equation for the reaction and (2)
- Determine the mass of water required to react with 14.0 g of aluminum carbide. (5)
- You have 42.04g of a sample of carbon. Calculate the number of moles in the carbon sample
- 2.If you have 4.257 mol of Al(OH)3, the number of molecules you have is
3. A Canadian penny contains 0.106 mol of copper. How many atoms of copper are in a Canadian penny?
4.Iron (II) oxide is used in mascara and eye shadow because it provides a brown colour to the product. “Pretty Eyes” mascara uses 0.15g of the Iron (II) oxide. Determine the number of “particles” (aka molecules) that would be present in the product.
5. Analysis of an ore of calcium shows that it contains 13.61g of calcium and 21.77g oxygen in a sample with a total mass of 46.28g. Calculate the mass percent of this compound.
6. Determine the % composition of Sodium Nitrate ?
The two tubes each contain N2O gas (P = 4.92 atm, V = 3 L, T = 300 K) and NH3 gas (P = 2.46 atm, V = 3L, T = 300 K). After the reaction is complete, the measured volume of nitrogen gas is under conditions where 3.2 grams of oxygen gas with a volume of 5 liters is
- Describe the steps involved in a sampling operation
