Representation of a Chemical Equation

Q.

Give an example of a reaction in which colour change is accompanied.

Q.

Balance the equation:-

C8H18+O2=CO2+H20

Q.

Why does the color of copper sulphate change when an iron nail is kept in it? Justify your answer.

Q. The balanced chemical equation for potassium reacting with water is:

1. $2\text{K}\text{(s)}+2{\text{H}}_2\text{O}\text{(l)}\to 2\text{KOH(aq)}+{\text{H}}_2\text{(g)}$
2. $2\text{K}\text{(s)}+{\text{H}}_2\text{O(l)}\to 2\text{KOH(aq)}+{\text{H}}_2\text{(g)}$
3. $\text{K}\text{(s)}+{\text{H}}_2\text{O}\text{(l)}\to \text{KOH(aq)}+{\text{H}}_2\text{(g)}$
4. $\text{K}\text{(s)}+2{\text{H}}_2\text{O(l)}\to \text{KOH(aq)}+{\text{H}}_2\text{(g)}$

Q.

Write a balanced chemical equation to represent the following reaction:
Iron reacts with steam to form Iron(II, III) oxide and hydrogen gas.

Q.

Write balance chemical equation for the following reaction: (a) hydrochloric acid reacts with calcium hydroxide . (b) calcium hydroxide reacts with sulphuric acid

Q.

How to balance a chemical equation by partial method

Q.

2g of silver chloride is taken in a china dish and the china dish is placed in sunlight for some time. What will be your observation in this case? Write the chemical reaction involved in the form of a balanced chemical equation. Identify the type of chemical reaction.

Q.

The reaction between copper sulphate solution and an iron nail is an example of ________ reaction.

Q. Balanced chemical equations are equations in which the number of each type of atoms on the reactant side may or may not be equal to the number of respective atoms on the product side.

1. False
2. True

Q. Upward arrow in a chemical equation represents _________.

1. formation of a precipitate
2. evolution of a gas
3. heat absorbed
4. heat released

Q.

Which of the following is the correct balanced chemical equation for the reaction of iron filings with steam?

1. 3Fe_(s) + H₂O_(l) → 3Fe₃O_4(s) + 4H_2(g)

2. 3Fe_(s) + 4H₂O_(g) → Fe₃O_4(s) + 4H_2(g)

3. Fe_(s) + H₂O_(l) → Fe₃O_4(s) + H_2(g)

4. Fe_(s) + 2H₂O_(g) → Fe₃O_4(s) + 2H_2(g)

Q.

Give an example of a chemical reaction for the following situation: A change in colour is observed.

Q.

what is blance chemical reaction ?

Q.

Cao (s) + $H_{2}O$ (l) → $Ca(OH{)}_2$ (aq) + heat.

What can be inferred from the above reaction?

(i) CaO is solid.

(ii) CaO is reactive with water.

(iii) $H_{2}O$ is liquid.

(iv) $H_{2}O$ is in vapour state.

(v) $Ca(OH{)}_2$ forms a solution with water

(vi) The reaction is Exothermic.

1. (i), (iii), (iv), (vi)

2. (i), (ii), (iii), (v), (vi)

3. (ii), (iii), (v), (iv)

4. (v), (iv)

Q.

Write a balanced chemical equation with state symbols for the following reaction:

(I) Solutions of Barium chloride and Sodium sulphate in water react to give insoluble Barium sulphate and a solution of Sodium chloride.

Q. The chemical equation will still remain balanced if all its coefficients are multiplied by a common natural number.

1. True
2. False

Q. What are balanced equations and why is it important to balance them

Q. Question 4
What is a balanced chemical equation? Why should chemical equations be balanced?

Q. How do catalysts work?

Q. Upward arrow in a chemical equation represents _________.

1. formation of a precipitate
2. evolution of a gas
3. heat absorbed
4. heat released

Q.

Write a balanced equation for the reactions that occur when:
(i) Iron react with steam.
(ii) Calcium and potassium react with water.

Q.

what is meant by skeletal equation ?why it should be balanced? balance some of the difficult skeletal equation?

Q.

You are given the following materials:

1. Iron nails
2. Copper sulphate solution

Identify the type of chemical reaction taking place when:

Iron nails when left dipped in blue Copper sulphate solution become brownish in colour and the blue colour of the Copper solution fades away.

Q.

${\mathrm{CuCO}}_3$(green) $\to$$\mathrm{CuO}$(black) +${\mathrm{CO}}_2$(g)

(a) What is the reaction type?

(b) Mention the physical state of the reactants and products.

Q.

Which of the following gas is produced when potassium bicarbonate reacts with sulphuric acid?

1. H₂

2. SO_2­

3. CO

4. CO₂

Q. A word equation contains the names and chemical formulae of the compounds involved in the reaction.

1. True
2. False

Q.

By writing chemical equations

Give two examples of chemical decomposition when a compound decomposes to form only elements.

Q.

How Many number of oxygen present in following equation?and also balance the following equation.

C5H11NH2+O2 gives CO2+H2O+NO2

Q. On balancing the chemical equation given below


The ratio p : s : t will be

नीचे दिये गये रासायनिक समीकरण को संतुलित करने पर


अनुपात p : s : t होगा

1. 1 : 1 : 2
2. 2 : 1 : 1
3. 1 : 1 : 1
4. 1 : 2 : 1