Writing Chemical Equation

Q.

Balance the reaction: ${\mathrm{Fe}}_2{\mathrm{O}}_3+\mathrm{CO}\to \mathrm{Fe}+{\mathrm{CO}}_2$

Q.

What is Le Chatelier's principle?

Q.

Explain POAC and its uses with one example?

Q.

What are the ways by which a chemical equation can be made more informative ?

Q. Which of the following equations does not follow the law of conservation of mass?

1. $2\mathrm{HCl}\to H_2+{\mathrm{Cl}}_2$
2. $H_2+O_2\to H_{2}O$
3. $\mathrm{Fe}+{\mathrm{ZnSO}}_4\to {\mathrm{FeSO}}_4+\mathrm{Zn}$
4. $H_2{\mathrm{CO}}_3\to H_{2}O+{\mathrm{CO}}_2$

Q.

52. Balance the following equation. Also name the products formed.
$\mathrm{Ag}+\mathrm{S}\to {\mathrm{Ag}}_2\mathrm{S}$

Q.

What type of chemical reaction when potassium iodide react with lead nitrate?

Q.

Is the change in enthalpy of a reaction always equal to heat transfer?

Q.

Match the physical state of elements or compounds to their symbols as used while writing chemical equations:

$\begin{array}{cc}\text{Physical State}& \text{Symbol}\\ \text{1. Gas}& \text{(A) (s)}\\ \text{2. Solid}& \text{(B) (g)}\\ \text{3. Liquid}& \text{(C) (aq)}\\ \text{4. Dissolved in water}\text{(solution with water)}& \text{(D) (l)}\end{array}$

1. B, E, D, C

2. E, B, C, D

3. B, D, E, C

4. C, D, E, B

Q. Which of these formulae are incorrect?

1. Ferric oxide - $F{e}_2{O}_3$
2. Ferric sulphate - $Fe(S{O}_4{)}_3$
3. Ferrous sulphate - $FeS{O}_4$
4. Ferrous oxide - $F{e}_2{O}_3$

Q.

15. An equation that gives the names of the substances involved in a reaction.

1. Chemical equation

2. Word equation

3. Chemical formula

4. Chemical symbol

Q.

Relate symbols used in Chemical reaction to their physical states.
$$\begin{array}{ccc}PhysicalState& & Symbol\\ Gas& \left(A\right)& \left(dw\right)\\ Solid& \left(B\right)& \left(g\right)\\ Liquid& \left(C\right)& \left(aq\right)\\ Dissolvedinwater\left(solutionwithwater\right)& \left(D\right)& \left(l\right)\\ & \left(E\right)& \left(s\right)\\ & \left(F\right)& \left(v\right)\end{array}$$

1. B, E, D, C

2. E, B, C, D

3. B, D, E, C

4. C, D, E, B

Q.

103. State the type of reaction taking place. Also balance the equation.

$\mathrm{K}+{\mathrm{H}}_2\mathrm{O}\to \mathrm{KOH}+{\mathrm{H}}_2$

Q.

Which coloured entity can be changed to balance the chemical reaction?

1. Entities in green

2. Entities in red

3. None of the colour

4. Entities in both red and green

Q. Saloni performed an activity by mixing equal amount of aqueous solutions of sodium sulphate and barium chloride in a test tube. She observed that
सलोनी ने एक परखनली में सोडियम सल्फेट तथा बेरियम क्लोराइड के जलीय विलयनों को समान मात्रा में मिलाकर एक क्रियाकलाप सम्पन्न किया। उसने प्रेक्षित किया कि

1. SO₂ gas is evolved
   SO₂ गैस मुक्त होती है
2. White precipitate of NaCl is formed
   NaCl का सफ़ेद अवक्षेप बनता है
3. Cl₂ gas is evolved
   Cl₂ गैस मुक्त होती है
4. White precipitate of BaSO₄ is formed
   BaSO₄ का सफ़ेद अवक्षेप बनता है

Q.

The chemical formula of Barium chloride and Alumnium sulphate are ______ and ______ respectively.

1. 

2. and

3. 

4. 

Q.

How can a chemical equation be made more informative?

Q.

Consider the following reaction.
$CaC{O}_3\left(s\right)$ + $H_{2}O\left(l\right)$ + $C{O}_2\left(g\right)$ $\to$ $Ca\left(HC{O}_3{)}_2\right(aq)$

$\begin{array}{cc}\text{Element}& \text{Number of atoms present}\end{array}$
$\begin{array}{ccc}& \text{Reactant side}& \text{Product side}\\ \text{Calcium}& 1& 1\\ \text{Carbon}& 2& \text{Y}\\ \text{Oxygen}& \text{X}& 6\\ \text{Hydrogen}& 2& 2\end{array}$
Recognise $\text{X}$ and $\text{Y}$. The value of $\text{X + Y}$ is___.

Q.

What will be the value of variable coefficients d, e, f, and g are considered for balancing the chemical equation.

1. d=2h

2. 3d=g

3. d=g

4. e=f

Q.

What is a method to indicate reactants and products of a chemical reaction using chemical formulas?

1. Chemical Equation

2. Chemical Equilibria

3. Periodic Table

4. Chemical Balance

Q.

Which coloured entity can be changed to balance the chemical reaction?

1. Entities in green

2. Entities in red

3. Entities in both red and green

4. None of the colour

Q.

Consider the following reaction.
$CaC{O}_3$ + $H_{2}O$ + $C{O}_2$ $\to$ $Ca(HC{O}_3{)}_2$

$\begin{array}{cc}Element& Numberofatomspresent\end{array}$
$\begin{array}{ccc}& Reactantside& Productside\\ Calcium& 1& 1\\ Carbon& 2& Y\\ Oxygen& X& 6\\ Hydrogen& 2& 2\end{array}$
Recognise $X$ and $Y$. The value of $X+Y$ is___.

Q.

What are the ways by which a chemical equation can be made more informative?

Q.

Products are represented on the left side of a chemical equation.

1. True

2. False

Q. What is Principal of atom conservation (POAC) ?

Q. When the state of a substance is written in brackets in a chemical reaction, “aq” stands for ___

1. Aqueous
2. Liquid
3. Unknown
4. Water

Q. Identify the type of the following reaction:

1. Precipitation Reaction
2. Neutralization Reaction
3. Combustion Reaction
4. Displacement Reaction

Q.

Identify the product formed and balance the equation

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2+{\mathrm{H}}_2{\mathrm{CO}}_3\to$

Q. What does the sign $\downarrow$ indicates in a chemical reaction. Also identify the type of reaction.

1. release of gas, displacement reaction
2. dissolution of gas, decomposition reaction
3. formation of a precipitate, precipitation reaction
4. lowering of temperature, decomposition reaction

Q.

Balance the equation

$$\begin{gathered} {\mathrm{NaNO}}_3\left(\mathrm{s}\right)\to {\mathrm{NaNO}}_2\left(\mathrm{aq}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\uparrow \\ (\mathrm{sodium}\mathrm{nitrate})(\mathrm{sodium}\mathrm{nitrite})\left(\mathrm{oxide}\right) \end{gathered}$$