Writing Chemical Equations

Q.

Write the balanced equation when phosphorous burns in oxygen to form phosphorous pentoxide.

Q.

Write the balanced chemical equation for the below reaction and identify the type of reaction in this case:

Thermite reaction- Iron (III) oxide reacts with Aluminum to give molten iron and aluminum oxide.

Q.

What does the symbol (aq) represent in a chemical equation ?

Q.

Translate the following statements into chemical equations and then balance the equations :

(a) Hydrogen sulphide gas burns in air to give water and sulphur dioxide.

(b) Phosphorus burns in oxygen to give phosphorus pentoxide.

(c) Carbon disulphide burns in air to give carbon dioxide and sulphur dioxide.

(d) Aluminium metal replaces iron from ferric oxide, $F{e}_2{O}_3$ , giving aluminium oxide and iron.

(e) Barium chloride reacts with zinc sulphate to give zine chloride and barium sulphate.

Q.

How will you indicate the following effects in a chemical equation ?

(a) A solution made in water

(b) Exothermic reaction

(c) Endothermic reaction

Q.

How can we make the chemical equation more informative?

Q.

When hydrogen is passed over copper oxide, copper and steam are formed. Write a balanced equation for this reaction and state which of the chemicals are :

(i) elements (ii) compounds (iii) reactants

(iv) products (v) metals (vi) non-metals

Q.

(a) Potassium chlorate $\left(KCl{O}_3\right)$ on heating forms potassium chloride and oxygen. Write a balanced equation for this reaction adn indicate the evolution of gas.

(b) Rewrite the following information in the form of a balanced chemical equation :

Magnesium burns in carbon dioxide to form magnesium oxide equation :

Q.

In which of the following reaction the physical state of the reactants or the product is not correctly represented?

1. ${\text{N}}_2\text{(g)}+3{\text{H}}_2\text{(g)}\leftrightharpoons 2{\text{NH}}_3\text{(g)}$

2. ${\text{SO}}_2\text{(g)}+{\text{Cl}}_2\text{(g)}\leftrightharpoons {\text{SO}}_2\text{(g)}$

3. $\text{Zn (s)}+\text{HCl (aq)}\leftrightharpoons {\text{ZnCl}}_2\text{(aq)}+{\text{H}}_2\text{(g)}$

4. ${\text{NH}}_3\text{(s)}+\text{HCl (aq)}\leftrightharpoons {\text{NH}}_4\text{Cl (s)}$

Q.

What is meant by skeltal type chemical equation? What does it represent ? Using thee equation for elecrolytic decompostion of water and also differentiate between skeltal chemical eqaution and a balanced chemical equation?

Q.

Write the balanced equation of reduction of copper oxide by hydrogen.

Q.

The autotrophic mode of nutrition requires

1. CO₂ and water

2. Chlorophyll

3. Sunlight

4. All of the above

Q. Write a balanced chemical equation with state symbols for the following reactions.
Sodium hydroxide solution (in water) reacts with a hydrochloric acid solution (in water) to produce sodium chloride solution and water.

Q.

A substance which increases the rate of a reaction and remains unchanged is called,

1. Reactant

2. Product

3. Catalyst

4. None of these

Q.

Substances that are formed as a result of a chemical reaction are called -------- and are written on the ---------- side of the equation.

Q.

Why is chemical equation is calcium carbonate and marble the same?

Q. What are the drawbacks of chemical equations?

Q.

Give the balanced equation for the action of heat on the following compound:

Iron (II) hydroxide.

Q.

Give the balanced chemical equations for the
above reaction.

Q.

Complete and balance the following reaction :

$\mathrm{Fe}+\mathrm{CuSO}4\to$

Q.

Give an example of an ion which is mono-atomic.

Q.

Write balanced equations for the reaction of dilute hydrochloric acid with each of the following :
(a) iron,
(b) sodium hydrogen carbonate,
(c) iron(II) sulphide,
(d) sodium sulphite,
(e) sodium thiosulphate solution.

Q.

Write the following equation and balance them.

Silver oxide + Hydrogen peroxide $\to$ Silver + Water + Oxygen

Q. (i) What happens when zinc granules are treated with dilute solution of $H_{2}S{O}_4$? Also write the chemical equations if reaction occurs.

(ii) What happens when zinc granules are treated with dilute solution of HCl? Also write the chemical equations if reaction occurs.

(iii) What happens when zinc granules are treated with dilute solution of $HN{O}_3$? Also write the chemical equations if reaction occurs.

(iv) What happens when zinc granules are treated with dilute solution of NaCl? Also write the chemical equations if reaction occurs.

(v) What happens when zinc granules are treated with dilute solution of NaOH? Also write the chemical equations if reaction occurs.

Q.

Which of the following is a polyatomic ion?

1. ${\mathrm{Zn}}^{2+}$

2. ${\mathrm{PO}}_4^{3-}$

3. ${\mathrm{Mg}}^{2+}$

4. ${\mathrm{Cr}}^{3+}$

Q.

The following equation is balanced: $\mathrm{CaOH}+\mathrm{HCl}\to \mathrm{CaCl}+{\mathrm{H}}_2\mathrm{O}$. Are you satisfied with it?

Q. How to balance the equation?

Q. The formula which expresses the smallest whole number ratio of the constituent atom within the molecule is called the

1. chemical formula
2. molecular formula
3. ionic formula
4. empirical formula

Q.

Balance the following chemical equation :
$Mn{O}_2+HCl\to MnC{l}_2+C{l}_2+H_{2}O$

Q.

In which of the following reaction the physical state of the reactants or the product is not correctly represented?

1. ${\text{N}}_2\text{(g)}+3{\text{H}}_2\text{(g)}\leftrightharpoons 2{\text{NH}}_3\text{(g)}$

2. ${\text{SO}}_2\text{(g)}+{\text{Cl}}_2\text{(g)}\leftrightharpoons {\text{SO}}_2{Cl}_2\text{(g)}$

3. $\text{Zn (s)}+\text{HCl (aq)}\leftrightharpoons {\text{ZnCl}}_2\text{(aq)}+{\text{H}}_2\text{(g)}$

4. ${\text{NH}}_3\text{(s)}+\text{HCl (aq)}\leftrightharpoons {\text{NH}}_4\text{Cl (s)}$