Chemistry Mock Yr11 Flashcards
(a) Fertilisers are sometimes added to soil.
(i) State why fertilisers are added to soil.
To make plant grow/faster/bigger
Fertilisers contain compounds of different elements.
Three of these elements have the symbols K, N and P.
K: potassium
N: nitrogen
P: phosphorus
What do you measure volumes of liquid
P: burette (1)
Q: pipette (1)
In the titration experiment, small volumes of dilute sulfuric acid are added
gradually to the ammonia solution in a flask.
Give the letter, P, Q or R, of the piece of apparatus in Figure 1 that should be
used to add the dilute sulfuric acid.
P / burette
The titration experiment is used to produce a solution of ammonium sulfate.
Describe how solid ammonium sulfate should be obtained from this solution.
use of Bunsen burner (1)
* until all water evaporates/
disappears (1)
* until some water evaporates
then leave (1)
* leave in warm place
If liquid water is cooled below 0°C it turns into the solid, ice.
(a) (i) Give the name for the change of state from liquid to solid.
freezing
Explain why this drinking water should not be described as pure water.
pure water contains {only water
(molecules)/ only one substance}
State the information from Figure 2 that shows that the drinking water is neutral
pH is 7
State how you know that calcium is a metal from its position in the periodic table
It is on left / in group 2 / column 2
Calculate the mass of calcium ions in 250cm3
of this drinking water.
250/1000 (1) (=0.250) * 60 x 250/1000 (1) (=15)
A torch contains a chemical cell.
The torch is turned on and then left on for many hours.
Describe what you would see happen when the torch is turned on and then left
for many hours.
bright light at start (1)
* fades/ gets dimmer (1)
* then goes out (1)
What type of reaction occurs when chromium reacts with oxygen?
D) oxidation
Hydrogen and oxygen are reactants in some fuel cells.
Which word equation shows the overall reaction that occurs in these fuel cells?
hydrogen + oxygen → water
Explain why covering iron tools with a thin layer of grease prevents rusting
- air/oxygen excluded (1)
- water excluded (1)
- air/oxygen/water needed for corrosion (1)
Sacrificial protection is another way of preventing rusting.
An example of sacrificial protection is when lumps of zinc are connected to
the iron-containing structure of an oil rig.
Explain how the zinc protects the iron from rusting.
zinc is more reactive (than iron) (1)
* so reacts instead (1)
Place the metals in order of reactivity from most to least reactive.
most reactive : magnesium..
Iron..
least reactive : Silver..
Hydrogen is given off when magnesium reacts with acid.
The hydrogen is tested by collecting the gas in a test tube and igniting it.
What is the safest way to ignite the gas?
put a lighted splint at the open end of the test tube is the only correct
answer
(iii) State the observation made in this test that shows that the gas is hydrogen
Squeeze-pop-test
if hydrogen present it will make a pop sound
Iron is extracted by heating iron oxide with carbon.
Electrolysis of molten iron oxide is not used to extract iron.
(i) State why iron can be extracted by heating iron oxide with carbon.
iron is less reactive (than carbon) ORA
What does the term isotope mean
Same number of proton different number of neurone
What does the term “Electrolysis”
splitting ironic compound
Elec- electricity
lysis- Latin way meaning the act of breaking/splitting.
State why electrolysis is not used to extract iron.
electrolysis is expensive/
more expensive method than heating with
carbon/
heating with carbon is cheaper/
electrolysis needs a large amount
of electricity
What’s the mass and relative charge for proton?
Mass : 1
Charge : +1
What’s the mass and relative charge for neurone?
Mass : 1
Charge : 0
What’s the mass and relative charge of electrons?
Mass : almost 0
Charge : 1/1860
How do you find the atomic number in an element?
The smallest number
What is hydrogen
- natural gas
What is nitrogen
- air
In a dynamic equilibrium two reactions occur at the same time.
These are the forward reaction and the ……………………………………………………. reaction.
The rates of the two reactions are ……………………………………………………. .
the.. backward
are..equal
the number of hydrogen molecules at equilibrium
4
the number of hydrogen molecules before reaction
10
the change in the number of hydrogen molecules.
-6
The reaction between nitrogen and hydrogen happens at a pressure of
200 atmospheres.
Another unit of pressure is Pascals, Pa (1 atmosphere = 101325 Pa).
Calculate the value of 200 atmospheres in Pascals.
101325 x 200 (1)
= 20265000 (Pascals) (1)
Complete the equation for this reaction.
(2)
……………………… +………………………. ⇌ 2 NH3
N2 + 3 H2 ⇌ 2 NH3
A student carries out an experiment to see how the pH changes when different
masses of solid B are added to dilute hydrochloric acid.
The student uses the following method.
step 1 use a measuring cylinder to measure out 100cm3
of dilute hydrochloric acid
step 2 pour the acid into a beaker
step 3 measure the pH with a pH probe
step 4 add half a spatula of solid B and stir
step 5 repeat steps 3 and 4 until the pH stops changing.
(i) Give a safety precaution that should be taken during the experiment.
wear safety goggles
OR gloves
Give an improvement to step 4 that would produce more accurate results.
Measure mass of solid
ORR… use a
specified mass of solid
(iii) What is the most likely change in pH during the experiment?
B) from 1 to 12 is the only correct answer.
) If some methyl orange indicator is added to the acid in step 2, the mixture
changes colour during the experiment.
State the colour change.
(2)
colour at start acid …………………………… colour at end ………………………
start: red/pink (1)
end: yellow (1)
What is the name of this piece of apparatus?
A) electrode
Give one reason why graphite is a suitable material to make Y
conduct electricity
) Complete the balanced equation for the reaction that occurs.
(1)
…………………………. HCl → H2+ Cl
2 HCl → H2 + Cl2
7 (a) This question is about the metal gold.
(i) Gold can be hammered into shape.
State the name of this property.
malleable
Gold alloys can be used to repair teeth.
One reason that gold alloys are used is that they can be hammered into shape.
Give one other reason why gold alloys are used to repair teeth.
insoluble/
unreactive/
inert /
non-toxic /
hard
A gold alloy contains 78% gold by mass.
Calculate the mass of gold in 2.00kg of this alloy.
Give your answer in grams.
(not given in question… but remember to convert kg to g which is X1000)
78 / 100 (1)
78 / 100 x 2.00 (1) (= 1.56 kg)
1.56 x 1000 (1) (= 1560 g)
Explain the observations and give reasons why the masses after heating are less
than expected.
Colour change
* copper is red brown
* black colour is copper oxide
Mass increase
* oxygen atoms are added
* oxygen atoms have mass
* increase in mass due to oxygen atoms
* powder heated for longer
* powder has more copper atoms exposed
* powder reacts more
* powder adds more oxygen atoms
* powder has larger mass increase
Mass increase less than expected
* copper is unreactive metal
* unreactive metals have slow reactions
* time not enough for reaction to be complete
* copper oxide only forms on surface so less forms on piece than
powder
* Bunsen flame not hot enough for full reaction
* some copper powder may be lost to air
* some copper oxide may be lost to air
What name is given to the process of mixing a solid with water to form a solution?
C) dissolving
Sodium reacts with hydrochloric acid to form sodium chloride and hydrogen.
(i) Write the word equation for this reaction.
sodium + hydrochloric acid → sodium chloride + hydrogen
Sodium chloride solution is neutral.
Give the pH of this solution.
7
) The pH of a sodium chloride solution was measured.
(i) State what could be used to measure the pH of a solution.
pH meter
Explain the importance of fertilisers in farming
- crops require fertilisers to grow
- promote plant growth
increased yield (means greater
profits)
A fertiliser is made by reacting ammonia with nitric acid.
What is the name of this fertiliser?
C) ammonium nitrate
The formula of ammonia is NH3.
State what the formula of ammonia shows about the number of nitrogen atoms
and the number of hydrogen atoms combined in a molecule of ammonia.
one nitrogen (atom) and three
hydrogen (atoms) (1)
Write the word equation for this reaction, including the correct symbol to
show that the reaction is reversible.
N² + 3H² ⇌ 2NH3
Aluminium oxide reacts with hydrochloric acid to form a salt and water.
(i) State the name of the salt formed.
aluminium chloride
In this reaction aluminium oxide is a base.
State the type of reaction that takes place when an acid reacts with a base
neutralisation
Gallium, Ga, is in the same group of the modern periodic table as aluminium.
The formula of aluminium oxide is Al2O3.
(i) Predict the formula of gallium oxide.
Ga²O ³
What type of substance is gallium oxide?
Ionic
What’s the process that goes from a from a gas to a liquid
condensation.
Gallium metal is a conductor of electricity.
Explain how metals conduct electricity.
electrons (1)
* able to move / are delocalised (1)
OR
produces an electrostatic force of attraction between the positively charged metal ions, and the negatively charged delocalised electrons.
In the 19th century, Mendeleev arranged the elements known at the time to form
his periodic table.
Mendeleev’s periodic table is different from the modern periodic table.
State one difference between Mendeleev’s periodic table and the modern
periodic table.
- arranged by order of (relative) atomic mass
- in Mendeleev’s early periodic table) gaps
missing elements /
-fewer elements / - noble
gases were not present
TRUE OR FALSE
iron can act as a catalyst
TRUE
TRUE OR FALSE
iron forms compounds that are coloured
TRUE
TRUE OR FALSE
iron has a low density
FALSE
TRUE OR FALSE
iron has a very high melting point
TRUE
Most iron produced is converted into alloys of iron.
(i) State why alloys have more uses than pure metals.
alloys stronger /
pure metals weaker /
/ alloys more corrosion resistant
How do you Calculate the mass of molybdenum
Multiply the molybdenum value
Times
sample of this alloy of iron
What of these metals is found as the uncombined element in the Earth’s crust?
b) Gold
Suggest an explanation for the shape of the graph
voltage decreases
* as transition
metal} used up
Give two advantages of recycling metals rather than extracting metals from their ores
1) Reduces waste
2) Recues energy waste needed for metal extraction.
