Find the moles of CaO
divide mass (2.0g) by the RFM which is 56 (Ca is 40 add that to O which is 16 making 56) this gives 0.0356 moles.
Find the theoretical mass by multiplying the moles of CaO (which is 0.0356 as there are no balancing number making the ratio 1:1) by the RFM of Ca(OH)2 which is 74 (40+16+16+1+1)
74 (Ca(OH)2 RFM) x 0.0357 (CaO moles) = 2.6g which is the theoretical mass of Ca(OH)2
Find percentage yield by dividing the actual mass of Ca(OH)2 by the theoretical and then x100 this Should give you 82.3%
Because copper has a higher electrical and thermal conductivity than iron and is not susceptible to oxidation as easily.
Answer:
The correct answer is option D.
Explanation:
Step 1: 
Step 2: 
Overall reaction can be determined by adding all the reactions of mechanism:

Reactants in an overall reaction = 
Products in an overall reaction = 
According to question , the role of oxygen gas is product.
Explanation:
The sum of all oxidation numbers in a neutral compound is zero. The sum of all oxidation numbers in a polyatomic (many-atom) ion is equal to the charge on the ion. The oxidation number of oxygen in a compound is usually –2. The oxidation state of hydrogen in a compound is usually +1.
The oxidation state of Al in Al(OH)
4
−
x+4(+1−2)=−1
∴x=+3
The oxidation state of Mn in MnO
2
y+2(−2)=0
∴y=+4
thank u