1.what effect would adding water (h2o) have on this reaction over time?

(nh4)2co3(s) ⇌ 2nh3(g) +co2(g) +h2o(g)

a.
the concentration of products would increase, and the concentration of reactants would decrease.
b.
the concentrations of both products and reactants would increase.
c.
the concentration of products would decrease, and the concentration of reactants would increase.
d.
the concentrations of both products and reactants would decrease.

2.which statement is true of a catalyst?

a.
it behaves as a reactant in a chemical reaction.
b.
it increases the temperature of a reaction.
c.
it decreases the concentration of the products.
d.
it accelerates the reaction rates of a mixture.

3.which statement is always true about a reversible chemical reaction?

a.
the concentration of reactants is higher than that of the products.
b.
the products can form reactants, and the reactants can form products.
c.
the concentrations of reactants and products are not constant.
d.
the concentration of the products is higher than that of the reactants.

4.classify the outcomes based on whether they are caused by adding or removing a reactant from a chemical reaction.

-the rate of the forward
reaction increases.

-the rate of the reverse
reaction increases.

-the concentration of
products increases.

-the concentration of
products decreases.

1) Water is one of the products in the given reaction. Based on Le Chatelier's principle addition of water will shift the equilibrium in a direction so as to undo the effect. Hence, the reaction will shift towards the reactant

Ans. C) Concentration of products would decrease and the reactants would increase.

2) Ans D) A catalyst accelerates the reaction rates of a mixture

3) A reversible reaction is one which can progress in the forward and reverse directions.

Ans B) The products can form reactants and the reactants can form products

4)

-The rate of forward reaction increases- ADDING REACTANT

- Rate of reverse reaction increases - REMOVING REACTANT

- Concentration of products increases- ADDING REACTANT

- Concentration of product decreases- REMOVING REACTANT

-

it is the most commonly accepted one

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.