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WorksheetsMiddles June revision quiz (moles, energetics and chemical tests
Total questions: 50
Worksheet time: 41mins
Which of the following is a chemical test for oxygen gas?
relights a glowing splint
bleaches damp litmus paper white
pops with a lit splint
turns limewater cloudy
Which of the following is a chemical test for hydrogen gas?
relights a glowing splint
turns limewater cloudy
bleaches damp litmus paper white
burns with a pop when lit splint is used
A gas turns damp red litmus paper blue. The gas is ....
sulfur dioxide
oxygen
ammonia
carbon dioxide
Sodium hydroxide solution can be added to an unknown solution to indicate the presence of....
Iron (II)
Iron (III)
Copper (II)
All of them
What is observed when sodium hydroxide is added to a solution of Fe2+ ions?
Green precipitate
Brown precipitate
Blue precipitate
White precipitate
In flame testing, what element gives a yellow flame
Carbon
Sodium
Copper
Lithium
When doing a flame test, what element gives a purple/lilac flame?
Barium
Calcium
Potassium
Copper
Chlorine gas.......
will turn limewater chalky
will turn damp blue litmus paper red then bleach it white
will burn with a pop
will turn damp red litmus blue paper
Ammonia gas.......
is acidic
is neutral
is alkaline
has a positive charge
A positive test for the presence of water shows what colour change for anhydrous copper sulphate
white to blue
blue to white
pink to blue
blue to pink
Which ion gives a white precipitate when first nitric acid is added, followed by silver nitrate solution?
nitrate
sulphate
chloride
iodide
Which ion gives a yellow precipitate when first nitric acid is added, followed by silver nitrate solution?
nitrate
sulphate
chloride
iodide
A student adds acid to a solid and nothing happens. What does this tell her about the solid?
It is completely unreactive
It is an acid
it is a base
it does not contain the carbonate ion
A positive test for the presence of water shows what colour change for anhydrous copper sulphate
white to blue
blue to white
pink to blue
blue to pink
Bubbling the gas through limewater and seeing the limewater turn cloudy is the test for which gas?
carbon monoxide
carbon dioxide
carbonate
hydrogen
What is the colour of the solid hydroxide formed when testing for copper(II) ions?
Blue
Green
Orange
Brown
What is produced by Fe3+ when NaOH is added?
Brown Precipitate
Green Precipitate
White Precipitate
No precipitate, but a gas that turns damp pink litmus paper blue
What is produced by Cl- when nitric acid and silver nitrate are added?
White Precipitate
Cream Precipitate
Yellow Precipitate
Fizzing
What is produced by Br- when nitric acid and silver nitrate are added?
White Precipitate
Cream Precipitate
Yellow Precipitate
Fizzing
What is produced when testing for sulfates with hydrochloric acid and barium chloride?
a white precipitate
carbon dioxide
hydrogen gas
copper (II) oxide
a squeaky pop
What is used to test for halides? (Cl⁻, Br⁻, I⁻)
Dilute Nitric Acid
Barium Chloride
Dilute Hydrochloric acid
Silver Nitrate solution
Sulphuric acid
An oxide of nitrogen has the following composition by mass: N, 30.4%; O, 69.6%.
It has a relative molecular mass of 92.
What is the molecular formula of the oxide of nitrogen?
(Ar N=14, O=16)
N2O3
NO2
N2O4
NO
Phosphorus forms another compound with hydrogen with the following composition by mass:
P: 93.94%, H: 6.06%
Calculate the empirical formula of the compound. (Ar P=31, H=1)
(You do not need to subscript the numbers)
(a)
The compound magnesium nitrate has the formula Mg(NO3)2.
What is the relative formula mass of magnesium nitrate?
(Ar Mg=24, N=14, O=16)
(a)
Which of the following is considered an empirical formula?
CH3COOH
C6H12O6
H2O
Mg2Cl4
What is the empirical formula of C4H6 ?
CH
CH3
C2H3
C4H6
If a chemical reaction releases heat to the surroundings, it is called an...
endothermic reaction
exothermic reaction
existential reaction
extinct reaction
In an endothermic reaction, the temperature of the surroundings...
Decreases
Increases
Stays the same
Combustion reactions are always what type of reaction?
endothermic
exothermic
existential
extinct
When acids react with alkalis exothermically. What happens to the temperature of the water that the reaction happens in?
Never stops increasing
Never stops decreasing
Always stays the same
Increases initially then decreases when the reaction finishes.
In the equation Q = mcΔT, what does Q stand for?
Sound energy
Light energy
Heat energy
Kinetic energy
In the equation Q = mcΔT, what does m stand for?
minutes
metres
mass (in grams)
momentum
In the equation Q = mcΔT, what does ΔT stand for?
Change of temperature
Change of time
2.0g of zinc metal is added to 50cm3 copper sulfate solution. When calculating the heat energy change for this reaction, what value of 'm' should be used?
2.0g
50g
52g
48g
2.0g of zinc metal is added to 50cm3 copper sulfate solution. The temperature rises by 23oC. If the specific heat capacity of the solution is 4.2, calculate the amount of heat energy released in kJ.
4830 J
4.83 kJ
193.2 J
0.1932 kJ
The molar energy change (called enthalpy, ΔH) is equal to:
Q/moles
Q x moles
Moles / Q
Moles + Q
For an exothermic reaction, the enthalpy change (ΔH) has what sign?
Positive
Negative
For an endothermic reaction, the enthalpy change (ΔH) has what sign?
Positive
Negative
A combustion reaction produces 1300J of heat energy when 0.1 moles of a fuel is burned. What is the enthalpy change of fuel in kJ/mol?
1.300/0.1 = 13.0 kJ/mol
1.300/0.1 = -13.0 kJ/mol
1.300 / 0.1 = +13.0 kJmol
1300 x 0.1 = -130 Jmol
The energy level diagram for the reaction between magnesium and hydrochloric acid is shown. Select the incorrect statement.
Energy is given out during the reaction
The products are at a lower energy level than the reactants
The reaction is endothermic.
The reaction is exothermic
Some white anhydrous copper(II) sulfate powder is put into a beaker of water and stirred. What would show that the process was exothermic?
A blue solution is formed
The beaker feels cooler
The beaker feels warmer
The heat produced when 0.01 mol of ethanol was burned raised the temperature of 100 g of water by 20°C. The specific heat capacity of water is 4.2 J g-1 K-1.
Which is the correct expression for the magnitude of the enthalpy of combustion of ethanol in J mol–1?
100 x 4.2 x 20
0.01
100 x 4.2 x 0.01
20
20 x 4.2 x 0.01
100
20 x 100 x 0.01
4.2
Which combination is correct for an endothermic reaction taking place in solution?
+ ∆H and temperature of solution increases
+ ∆H and temperature of solution decreases
- ∆H and temperature of solution increase
- ∆H and temperature of solution decreases
Which of the following is correct about the energy changes during bond breaking and bond formation?
Bond breaking - exothermic
Bond forming - endothermic
Bond breaking - exothermic
Bond forming - exothermic
Bond breaking - endothermic
Bond forming - endothermic
Bond breaking - endothermic
Bond forming - exothermic
What is the temperature rise when 2100 J of energy is supplied to 100 g of water? Specific heat capacity of water = 4.12 J g-1K-1
5oC
278 K
0.2 oC
20 oC
Which equation is right to calculate the energy change in a reaction?
Bonds formed - bonds broken
Bonds made - bonds broken
Bonds broken - bonds formed
Which statement is CORRECT?
Bonds require energy to form them but release energy when broken
Bonds require energy to form them and require energy to break them
Bonds release energy when formed them but require energy to break
Bonds release energy when formed and release energy when broken
Using the table of average bond energies below the image, the ΔH for the reaction in kJ is.....
+ 160 kJ
-63 kJ
- 160 kJ
-217 kJ
If a reaction is exothermic overall, then more energy has been released during bond making than has been required for bond breaking.
If a reaction is endothermic overall, then more energy has been required during bond breaking than has been released during bond making.
Both answers are True
Both answers are false
Only the top answer is true
Only the bottom answer is true
