Answer:
1) 0.3g Mg
2)0.5g MgO
3)0.2g O
4)0.01mol Mg & 0.01mol O
5)0.01mol MgO
6) Empirical formula MgO
Explanation:
The mass og Mg is obtained by substracting 24.36g from 24.66g:
24.66 - 24.36 = 0.3g Mg
The ignition of Mg means that it's reacting with oxygen to form an oxide. The increase in the crucible mass after the Mg ignition is due to the addition of oxygen. However, the addition of few drops of water produces a new compound: a hydroxide. According to the oxidation state og Mg (2+), the only magnesium oxide possible is MgO. It happens because the oxidation state of oxygen in oxides is 2-. Which means that just one oxygen atom is required to electrically neutralize one magnesium atom.
We can use a conversion factor to know how much MgO is made from from 0.3 g of Mg:
*
= 0.2g O
Thereby the mass of the oxide is 0.2g O + 0.3g Mg = 0.5g MgO
We convert the mass of oxygen and magnesium to the respective amounts in moles by using conversion factors:
*
= 0.01mol O
*
= 0.01mol Mg
The moles of MgO can be obtained from:
*
= 0.01mol MgO
To obtain the empirical formula, the amount fo moles of each elements must be divided by the smallest one, in this case, 0.01.
The result for both number of Mg atoms and O atoms is 1. This can be interpreted to mean that there is a Mg atom for each O atom forming the formula unit of the compound.
The step when water is added to the compound resulting after heating does not affect the calculations necessary for the magnesium oxide.
Reactant: carbon dioxide and sodium phenoxide
product: sodium salicylate
Answer: a.
:
is negative
b.
:
is negative
c.
:
is negative
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa
a) 
In this reaction 2 moles of gaseous reactants are converting to 1 mole of gaseous products. The randomness will decrease and hence entropy will also decrease. Thus
is negative.
b) 
In this reaction solid reactants are converting to aqueous products. The randomness will increase and hence entropy will also increase. Thus
is positive.
c) 
In this reaction aqueous reactants are converting to solid products. The randomness will decrease and hence entropy will also decrease. Thus
is negative
Answer:
yes the answer is true because heat changes duriing epalthy change
Answer:
MgO + 2 HNO3 → Mg(NO3)2 + H2O
Explanation: