TEST
Basics ( 1 point for each part)
1) Calculate the Mr of a)Al2(SO4)3 b)ZnSO4.6H2O
2) Calculate the moles present in a) 25g NaOH
3) Calculate the mass of NaOH in a) 0.25 mol of NaOH
b) 1.123g of NaOH
b)125mol of NaOH
Multiple choice
4) ethyne is C2H2 . It has a % of carbon of a) 12/24 x 100 b) 24/26 x 100 c) 50% d) 26/24 x 100
5)A chemical has an empirical formula of CH2O. Which of the following can it not be? a)Ribose, C5H10O5
b) Ethanoic acid, CH3COOH c) Banana flavor C5H11OOCH3 d) Antifreeze, CHOHCHOH
6) When the reaction is A + 2B ---- 2C I react 0.5 moles of A with 0.7 moles of B and find that I produce
0.7 moles of C. What is the percent yield of C? a) 100% b) 140% c) 70% d) less than 70%.
8) 0.25 moles of X has a mass of 14g. Which of the following could be X? a) CO 2 b) KOH c) C4H8 d) NaCl
Structures questions
9)Chemical Z consists of 32% Na, 23% S and 45% O by mass. Calculate its empirical formula. (3)
b) A student claims that Z is sodium tetrathionate, Na2S4O6 . Is the student correct, possibly correct or
wrong? Explain. (2)
10) CH4 + 2O2 ---- 2H2O + CO2 . If I react 10 g of methane with 10g of oxygen gas , calculate
a) moles of each (2 points)
b) limiting reagent, showing your working(2 )
c) maximum mass of water produced(2)
11) List 3 different reasons why in a laboratory investigation, getting a 100% yield of product is almost
impossible.(3)
12) In the production of aspirin the following reaction occurs:
C6H4 (COOH)OH + CH3 CO2COCH --- C6H4 (COOH)OOCCH3 + CH3COOH
Salicylic acid
ethanoic anhydride
aspirin
ethanoic acid
a)
What is the molar mass of salicylic acid in grams?(1)
b) If 0.25 moles of salicylic acid was reacted with 0.45 moles of ethanoic anhydride, what is the
maximum # of moles of aspirin could be produced? (1)
c)
Given that the molar mass of aspirin is 180g/mol and that the student collected 39g of aspirin,
determine the # of moles of aspirin produced. (1)
d) Determine the % yield of aspirin(1)
Test on Section1
1) How many moles are there in a) 35g of Ca(OH) 2 b) 25cm3 of 0.020M solution
2) What is the molarity if I have a) 2 moles in 250 cm3of solution
100cm3
b) 6.00g of NaOH in
3) What volume of solution can I make if I have a) 2 moles of chemical and I want an
0.5M solution
b) 2.46g of NaOH and I want a 0.025M solution
Multiple choice
4) If I triple the pressure on 400cm3 of gas and double its absolute temperature, what
volume should I end up with? A)267cm3 b) 600cm3 c) 300cm3 d) 167cm3
5) If I explode 40 cm3 of organic gas with 150 cm3 of oxygen and produce 80cm3 of CO2
and 120 cm3 of steam. If 30 cm3 of oxygen is left over what is the formula of the gas? A)
C2H6 b) C2H6O c) C2H3O d) CH2 O2
6) A litre of water weighs 1000g, so what is the molarity of pure water? A) 18 b) 1000 x
18 c) 1000/18 d) 18/1000
7) The empirical formula of X is CH2O. Which of the following could X be?
i) HCHO ii) CH2OH iii) HCOOCH3 .
a) I only b) any of the above c) I and iii only d) iii only
8) If 100cm3 of solution contains 0.01 moles, the molarity is a) 100 b) 10 c) 0.1 d) 0.01(
all mol per dm3 )
9) When making up 1000cm3 of 2.0M solution, how much water do I add? A) exactly
1000cm3 b) about 998cm3 c) about 1002cm3 d) The important thing is to make exactly
1000cm3 of solution and not know the exact volume of water used.
10) If I have two solutions, A and B, of the same molarity that react together in the ratio
1A :2B. If I have 10 cm3 , how much B will react fully with it? A) 5cm3 b) 10cm3 c)
15cm3 d) 20cm3.
11) Before use, a burette should be washed out with a) tap water b) distilled water c) the
solution that will go in the flask d) The solution that will go in the burette.
Longer response questions
12) A gas was collected and found to occupy 186cm3 at 1.02 x105 Pa and 25C. Calculate
the # of moles of gas(2)
13) Vitamin C is 40.9% C; 54.5% O and 4.54% H and has a molar mass of 180g +/-20.
Determine its empirical and molecular formula (4)
14) The blue protein laccase is found in wood rotting fungi and contains 0.39% Cu by
mass. If each molecule of laccase contains 4 copper ions, what is the molar mass of this
protein to the nearest 1000? (2)
15) Draw sketch graphs to show the relationship in gases with the first species on the y
axis( P = pressure; V = volume; T = temperature) (4)
a) P against T
c) P against V
b) PV against V
d) V against T
11)Chemical Z consists of 29% Na, 41% S and 30% O by mass. Calculate its empirical
formula. (3)
b) A student claims that Z is sodium tetrathionate, Na2S4O6 . Is the student correct,
possibly correct or wrong? Explain. (2)
12) 2H2 + O2 ---- 2 H2O . If I react 10 g of hydrogen gas with 4g of oxygen gas ,
calculate
a) moles of each (2 points) b) limiting reagent (2 ) and c) maximum mass of water
produced(2)