Reactivity of Metal

Question 1

Why do Group 1 elements have similar chemical properties?

Answer 1

they have the same number of outer shell electrons

Question 2

Give two observations you could make when sodium reacts with water.
Write your answers in Table 2.

Answer 2

any two from:
* bubbles (very) quickly
* melts (into a ball)
* floats
* moves (very) quickly

Question 3

How does the reactivity of the elements change going down Group 1?

Answer 3

(reactivity) increases (down the group

Question 4

• Evaluate the three possible methods for extracting tungsten from tungsten
  oxide.

Answer 4

carbon and iron are the cheapest reactants
* hydrogen is the most expensive reactant
* separating solid products is expensive
* separating solid products is time consuming
* in method 1, tungsten needs to be separated from tungsten
carbide
* in method 1, some tungsten is lost as tungsten carbide
* in method 1, the carbon dioxide produced will escape
* in method 2, the water vapour produced will escape
* in method 2, no separation of solids is needed
* in method 3, tungsten needs to be separated from iron oxide

Question 5

Give two observations you could make when a small piece of potassium is
added to water

Answer 5

(potassium) floats
* (potassium) melts
* (potassium) moves around
* potassium becomes smaller
allow potassium disappears
* (lilac) flame
* effervescence

Question 6

Explain why the reactivity of elements changes going down Group 1.

Answer 6

reactivity increases (going down the group)
1
(Because) the outer electron/shell is further from the nucleus
(so) there is less attraction between the nucleus and the outer electron/shell
(so) the atom loses an electron more easily

Question 7

Explain why sodium oxide has a high melting point.

Answer 7

giant structure

(with) strong (electrostatic) forces of attraction between ions

(so) large amounts of energy are needed to break the bonds / forces

Question 8

Describe a method the student could use to compare the reactivity of metal
Q with that of zinc.

Answer 8

measure temperature change

when each metal is added to silver nitrate solution

same concentration / volume of solution

same mass / moles of metal

the greater the temperature change the more reactive

Question 9

transition metals:

Answer 9

they form ions with different charges

they have high melting points

Question 10

A student added copper metal to colourless silver nitrate solution.
The student observed:
* pale grey crystals forming
* the solution turning blue.
Explain how these observations show that silver is less reactive than
copper.

Answer 10

the (grey) crystals are silver

the copper ions (produced) are blue

(because) copper displaces silver

Question 11

A student is given three metals, X, Y and Z to identify.
The metals are magnesium, iron and copper.
Plan an investigation to identify the three metals by comparing their
reactions with dilute hydrochloric acid.
Your plan should give valid results.

Answer 11

add the metals to (dilute) hydrochloric acid
compare rate of bubbling

for copper:
* no reaction
* shown by no temperature change

for magnesium and iron:
* magnesium increases in temperature more than iron

Control variables
* same concentration / volume of hydrochloric acid
* same mass / moles of metal

Question 12

What is meant by ‘activation energy’?

Answer 12

the (minimum) energy needed for particles to react

Question 13

Explain why aluminium is extracted using electrolysis and not by reduction
with carbon.

Answer 13

aluminium is more reactive than carbon

(so) carbon cannot displace aluminium

Question 14

Y is an unknown metal.
Describe a method to find the position of Y in the reactivity series

Answer 14

add the unknown metal to copper sulfate solution (1)
measure temperature change (1)
place the metals in order of temperature change
make sure to use same volume of solution

Question 15

Iron is a transition metal.
Sodium is a Group 1 metal.
Give two differences between the properties of iron and sodium.

Answer 15

iron has a high(er) melting / boiling point
* iron is dense(r)
* iron is hard(er)
* iron is strong(er)
* iron is less reactive
* iron can be a catalyst

Question 16

Titanium chloride is a liquid at room temperature.
Explain why you would not expect titanium chloride to be a liquid at room
temperature.

Answer 16

metal chlorides are usually ionic
(so)(metal chlorides) are solid at room temperature
(so)(metal chlorides) have high melting points
(because) they have strong (electrostatic) forces between the ions

Question 17

Name the element used to reduce iron oxide.

Answer 17

carbon

Question 18

Give one observation the student could make that shows there is a reaction between zinc
and copper sulfate.

Answer 18

brown / orange / dark deposit on zinc

Question 19

The temperature rose when the metals were added to sulfuric acid.
Give one other observation that might be made when the metal was added to sulfuric acid.
How would this observation be different for the different metals?

Answer 19

bubbles of gas

more (bubbles) seen with calcium than other metals

Question 20

The magnesium needed heating before it would react.
What conclusion can you draw from this?

Answer 20

The reaction has a high activation energy

Question 21

Suggest two reasons why copper should not be disposed of in landfill sites.

Answer 21

copper ores are limited/running out
allow copper is running out
* copper can be recycled
* copper can be reused
* copper is expensive

Question 22

Suggest why a 2 p coin made in 1991 is worth 3.3 p.

Answer 22

high cost of copper
*less copper available
* high demand for copper

Question 23

The alloy stainless steel is used instead of pure iron for the ball of the pen. why?

Answer 23

stainless steel) is hard /strong / durable

(stainless steel) resistant to corrosion o