Question

during the experiment, a student did not follow the procedure exactly as directed how will eact of these actions affect the weight of magnesium oxide( 7 on the report sheet)?

a-fumes were allowed to escape from the crucible(what is the compostion of the fumes)

b-water was not added to the crucible

c-the evaporation of water cused spattering

d-water was not completely removed by evaporation

2- the white powder often found on objects made of alminum is alminum oxide AL2O3 calculate the molar mass of the alminum oxide. if you wanted to make a molar quantity of alminum oxide in the lab how many Grams of alminum would you neeed to begin with?

3-a form of iron oxide commonrust has the formula Fe2O3 write a balanced equiation for its formation where would the oxygen come from?

4- if this experiment was carried out exactly as directed in the procudre section by a student in austrila for example should that student come up with a formula for the magnesium oxide other than MGO? why not ?

Answer 1

Solutions are as follows

during the experiment, a student did not follow the procedure exactly as directed how will eact of these actions affect the weight of magnesium oxide( 7 on the report sheet)?

a-fumes were allowed to escape from the crucible(what is the compostion of the fumes)

Solution :- The fumes produced from the reaction are the fumes of the gas that is produced by the reaction this will not affect the composition of the magnesium oxide.

b-water was not added to the crucible

Solution:- If the water is not added to the crucible then Mg metal would not convert to the magnesium oxide. Therefore product is not formed.

c-the evaporation of water cused spattering

Solution:- If the splattering of water is happened then it may also lose some amount of the magnesium metal from the reaction mixture or it may also lose the product formed during the reaction which causes the lower amount of the product.

d-water was not completely removed by evaporation

Solution :- If the water is not completely evaporated from the product then water remained in the product will add up to the mass of the product which gives the higher mass of the product than actually formed.

2- the white powder often found on objects made of alminum is alminum oxide AL2O3 calculate the molar mass of the alminum oxide. if you wanted to make a molar quantity of alminum oxide in the lab how many Grams of alminum would you neeed to begin with?

Solution :-

Molar mass is the sum of atomic masses of the elements present in the formula

Molar mass of Al2O3 = (2*Al)+(3*O)

                                    = (2*27)+(3*16)

                                    = 102 g per mol

Balanced reaction equation is as follows

4 Al + 3 O2 ---- > 2Al2O3

If we want to make 1 mole of Al2O3 then we need to use 2 moles of the Al

Therefore mass of Al needed = 2 mol * 27 g per mol = 54 g

So we need to start with 54 g Al

3-a form of iron oxide commonrust has the formula Fe2O3 write a balanced equiation for its formation where would the oxygen come from?

Solution :-

Balanced reaction equation is as follows

4 Fe(s) + 3O2(g) ------ > 2Fe2O3(s)

Oxygen is used from the atmosphere that is from air.

4- if this experiment was carried out exactly as directed in the procudre section by a student in austrila for example should that student come up with a formula for the magnesium oxide other than MGO? why not ?

Solution :-

The formula of the magnesium oxide will still MgO wherever the experiment is done because the composition of the compound does not changes. According to the law of constant composition.

The Mg and oxygen will combine in 1 :1 ratio to form the MgO as the oxide of magnesium.