Question

The correct formula form sometimes in this experimenti 0.9 Mg to 1.0 0) In that case, it mean sium oxide is MgO, a 1.0 to 1.0 ratio. But periment the ratio of Mg to O comes out too low. (Example se, it means that there was too much oxygen relative 1 f magnesium. At other times it comes out that the ratio is too large A vould be: 1.2 to 1.0 (Mg to O). In such a case it must be that there has - too little weight at the end of the experiment, which the mass of magnesium. At other times it comes example would be: 1.2 to 1.0 (Mg to been too little oxygen (or too little weigh registers as too little oxygen.) se below, decide whether the situation described would lead to a ulated ratio of too much oxygen, or too little oxygen, and explain your reasoning. (The calculated ratio contains the mistake.) Pistting in more water than is needed for reaction 3, and then not drying out excess water. b. Having some Mg(OH)2 left in the crucible instead of converting it to MgO. c. Having some Mg3N2 in the crucible as product, instead of pure MgO. d. Forgetting to weigh the cover along with the crucible and contents at the en

Answer 1

2. a. Water molecules have one oxygen atom. Putting in more water than needed for the reaction and then not drying water properly leads to the presence of extra oxygen atoms in the system. which leads to calculated ratio of too much oxygen.

b. Mg(OH)2 has two oxygen atoms in it and MgO has one oxygen atom in it. Therefore the presence of excess Mg(OH)2 will increase the ratio of oxygen to magnesium in MgO. As a result calculated ratio of oxygen will be too much.

c. Mg3N2 has three magnesium atoms with no oxygen atom. Therefore presence of Mg3N2 as product will increase the ratio of magnesium to oxygen during calculation which will lead to the calculation ratio of too little oxygen to magnesium.

d. Forgetting to weigh the cover and the crucible would not change the magnesium and oxygen ratio as the the cover and crucible contains MgO which have 1:1 ratio of magnesium and oxygen. Therefore magnesium and oxygen remains 1.0 to 1.0.

e. MgO is an ionic solid and have very high temperature stability (melting point 2852 oC). On the other hand Mg(OH)2 has much lower thermal stability (melting point 350 oC). Therefore the dense white smoke escaping from the crucible during burning is for Mg(OH)2 which is forming by the reaction of equimolar amount of MgO and H2O in the crucible. Consequently the ratio of magnesium to oxygen would not change and remains as 1.0 to 1.0 ratio.