Photo AI

The element magnesium, Mg, proton number 12, is a metal which is used in many alloys which are strong and light - CIE - A-Level Chemistry - Question 1 - 2010 - Paper 1

Question 1

The element magnesium, Mg, proton number 12, is a metal which is used in many alloys which are strong and light. Magnesium has several naturally occurring isotopes. ... show full transcript

Worked Solution & Example Answer:The element magnesium, Mg, proton number 12, is a metal which is used in many alloys which are strong and light - CIE - A-Level Chemistry - Question 1 - 2010 - Paper 1

Step 1

What is meant by the term isotope?

96%

114 rated

Answer

An isotope refers to atoms of the same element that have the same number of protons (atomic number) but different numbers of neutrons. This results in different mass numbers for the isotopes.

Step 2

Complete the table below for two of the isotopes of magnesium.

99%

104 rated

Answer

Isotope	Number of Protons	Number of Neutrons	Number of Electrons
24Mg	12	12	12
26Mg	12	14	12

Step 3

Calculate the relative atomic mass, Ar, of magnesium in the sample.

96%

101 rated

Answer

To calculate the relative atomic mass, we use the formula:

$A_r = \frac{(24 \times 78.60) + (25 \times 10.11) + (26 \times 11.29)}{100}$

Calculating each term separately:

For 24Mg: $24 \times 78.60 = 1896.40$
For 25Mg: $25 \times 10.11 = 252.75$
For 26Mg: $26 \times 11.29 = 293.54$

Adding these together gives:

$A_r = \frac{1896.40 + 252.75 + 293.54}{100} = 1868.69$

Thus, the relative atomic mass of magnesium in the sample, rounded to four significant figures, is $24.33.$

Step 4

Construct a balanced equation for the reaction between magnesium and chlorine.

98%

120 rated

Answer

The balanced equation for the reaction between magnesium and chlorine is:

$Mg + Cl_2 \rightarrow MgCl_2$

Step 5

Calculate the amount, in moles, of antimony atoms that reacted.

97%

117 rated

Answer

To calculate the amount of antimony in moles:

$n(Sb) = \frac{mass}{molar\ mass} = \frac{2.45}{122} = 0.0200$

Step 6

Calculate the amount, in moles, of chlorine atoms that reacted.

97%

121 rated

Answer

From the mass of the chloride A formed:

Calculate the mass of chlorine: $mass\ of\ Cl = mass\ of\ A - mass\ of\ Sb$ $mass\ of\ Cl = 4.57 - 2.45 = 2.12 g$
Using molar mass of Cl (35.5 g/mol): $n(Cl) = \frac{2.12}{35.5} = 0.0597$

Step 7

Use your answers to (i) and (ii) to determine the empirical formula of A.

96%

114 rated

Answer

Using the mole ratios calculated:

Moles of Sb = 0.0200
Moles of Cl = 0.0597

The ratio is approximately: $Sb : Cl = 0.0200 : 0.0597 \approx 1 : 3$ Thus, the empirical formula of A would be $SbCl_3$ .

Step 8

Construct a balanced equation for the reaction between antimony and chlorine.

99%

104 rated

Answer

The balanced equation for the reaction between antimony and chlorine is:

$2Sb + 3Cl_2 \rightarrow 2SbCl_3$

Step 9

What type of bonding is present in magnesium chloride?

96%

101 rated

Answer

The type of bonding present in magnesium chloride is ionic bonding.

Step 10

Suggest what type of bonding is present in A.

98%

120 rated

Answer

The type of bonding present in compound A (SbCl3) is covalent bonding.

Join the A-Level students using SimpleStudy...

97% of Students

Report Improved Results

98% of Students

Recommend to friends

100,000+

Students Supported

1 Million+

Questions answered

The element magnesium, Mg, proton number 12, is a metal which is used in many alloys which are strong and light - CIE - A-Level Chemistry - Question 1 - 2010 - Paper 1

Worked Solution & Example Answer:The element magnesium, Mg, proton number 12, is a metal which is used in many alloys which are strong and light - CIE - A-Level Chemistry - Question 1 - 2010 - Paper 1

What is meant by the term isotope?

Complete the table below for two of the isotopes of magnesium.

Calculate the relative atomic mass, Ar, of magnesium in the sample.

Construct a balanced equation for the reaction between magnesium and chlorine.

Calculate the amount, in moles, of antimony atoms that reacted.

Calculate the amount, in moles, of chlorine atoms that reacted.

Use your answers to (i) and (ii) to determine the empirical formula of A.

Construct a balanced equation for the reaction between antimony and chlorine.

What type of bonding is present in magnesium chloride?

Suggest what type of bonding is present in A.

Join the A-Level students using SimpleStudy...

Other A-Level Chemistry topics to explore