Answer:
1,070.41 grams of DDT will be formed .Explanation:
1) 
Moles of chlorobenzene = 
According to reaction, 2 moles of chloro benzene reacts with 1 mole of chloral . Then 10.64 moles of chloro benzene will react with :
of chloral
2) Moles of chloral = 
According to reaction, 1 moles of chloral reacts with 2 mole of chlorobenzene . Then 3.0915 moles of chloral will react with :
of chloro benzene
As we can see that chloral is in limiting amount and chloro benzene is in excessive amount. So, amount of DDT will depend upon amount of chloral.
According to reaction, 1 mole chloral gives 1 mole DDT.Then 3.0195 moles of chloral will give :

Mass of 3.0195 moles of DTT :
3.0195 mol × 354.5 g/mol = 1,070.41 g
1,070.41 grams of DDT will be formed .
The balanced chemical reaction:
<span>Cu + 2AgNO3 = Cu(NO3)2 + 2Ag
</span>
We are given the amount of the reactants to be used for the reaction. These values will be the starting point of our calculations.
9.85 g Cu ( 1 mol Cu / 63.55 g Cu ) = 0.15 mol Cu
31.0 g AgNO3 ( 1 mol AgNO3 / 169.87 g AgNO3 ) = 0.18 mol AgNO3
The limiting reactant is AgNO3.
0.18 mol AgNO3 ( 1 mol Cu(NO3)2 / 2 mol AgNO3 ) (187.56 g / 1 mol) =16.88 g Cu(NO3)2
0.15 mol Cu - 0.18 mol AgNO3 ( 1 mol Cu / 2 mol AgNo3) = 0.06 mol Cu excess
<span>0.06 mol Cu ( 63.55 g Cu / 1 mol Cu ) = 3.81 g Cu excess</span>
They cause most of their damage when they reach land
Alkynes are hydrocarbons with at least one triple covalent bond.