Explanation:
The first involves keeping the surface of the concrete moist by the use ponding, spraying/sprinkling, damp sand or damp hessian.
The second prevents the loss of moisture from the concrete by covering it with polythene sheeting or leaving the formwork in place.
The third involves the use of spray or roller applied curing compounds.
Answer:
Chlorophyll
Explanation:
Chlorophyll is the substance what gives green color for plants, also the molecule that is responsible for facilitating the process of photosynthesis.
The lead acid battery produces energy by oxidation of lead. The amount of lead oxidized in this case is 1.47 g.
<h3>What is lead acid battery?</h3>
The lead acid battery is the common accumulator that we have in use. It is made up of a cell that contains lead electrodes in an acid.
The oxidation of lead occurs according to thr equation;
Pb(s) ----> Pb^2+(aq) + 2e
If 207 g of Pb is oxidized by 2(96500)C
x g of lead is oxidized by (221 * 6.20) C
x = 207 g * (221 * 6.20) C/2(96500)C
x = 1.47 g
Learn more about lead acid battery: brainly.com/question/8341588
Answer:
- 58 kJ
Explanation:
The equation of the reaction is given as;
2NO2(g) → N2O4(g)
N2(g) + 202(g) → 2NO2(g) delta H = 67.7 kJ
Since NO2 is the reactant in the equation, we have to reverse this reaction. We now have;
2NO2(g) → N2(g) + 202(g) delta H = - 67.7 kJ
N2(g) + 202(g) → N2O4(g) delta H = 9.7 kJ
Since NO4 is the product in the equation, we don't have to do anything to this reaction.
Adding the two reactions;
2NO2(g) → N2(g) + 202(g) delta H = - 67.7 kJ
N2(g) + 202(g) → N2O4(g) delta H = 9.7 kJ
---------------------------------------------------------------- N2(g) and 2O2 (g) cancels out
2NO2(g) → N2O4(g) delta H = (-67.7 + 9.7) = - 58 kJ
The correct answer is an ionic bond