Writing Chemical Formula

Q. Which of the following represents sulphite ion?

1. $S{O}_4^{2-}$

2. $S{O}_3^{-}$

3. $S{O}_3^{2-}$
4. $S{O}_4^{-}$

Q.

A compounds chemical formula is Fe₂O₃ . Name the elements present in this compound. Name the compound represented by this formula.

Q.

What is the formula for copper (II) oxide?

1. CuO₂

2. CuO

3. Cu₂O₂

4. Cu₂O

Q.

Complete the following statements by selecting the correct option :

(a) The formula of a compound represents

(i) an atom (ii) a particle

(iii) a molecule (iv) a combination.

(b) The correct formula of aluminium oxide is

(i) AIO${}_3$ (ii) AIO${}_2$ (iii) AI${}_2$O${}_3$

(c) The valency of nitrogen in nitrogen dioxide (NO${}_2$) is

(i) one (ii) two

(v) three (iv) four.

Q.

What is the criss cross method of the formula of magnesium nitride

Q. Calculate the number of molecules of sulphur $\left(S_8\right)$ present in 16 g of solid sulphur.

Q. Question 6(a)
Calculate the molar mass of the following substances:
$\left(a\right)Ethyne,C_2{H}_2$

Q.

Which of the following represents a correct chemical formula? Name it.

1. $\mathrm{CaCl}$

2. ${\mathrm{BiPO}}_4$

3. ${\mathrm{NaSO}}_4$

4. $\mathrm{NaS}$

Q.

What is the chemical formula ? What is the rule for writing a formula correctly ?

Q.

What is the mass of 3 moles of $O_2$?

Q. An element $\text{X}$ forms an oxide ${\text{XO}}_3$. What can be the valency of element $\text{X}$?

1. 5
2. 6
3. 4
4. 2

Q. Identify the correct formula of sodium sulphate.

1. $N{a}_{2}S{O}_4$
2. $N{a}_{2}S{O}_3$
3. $N{a}_{2}C{O}_3$
4. $NaOH$

Q.

Choose the correct option, regarding IUPAC names?

1. Many of the symbols are the first one or two letters of the element’s name in English

2. The first letter of a symbol is always written as a capital letter (uppercase) and the second letter in lower case.

3. Some of the Elements are named as per their Latin names

4. All of the above

Q.

While naming a compound consisting of a metal and non-metal, usually the ___is written first and ___is written next.

Q. The chemical symbols of lead and mercury are ____ and ____ respectively.

1. Pb, Hg
2. Le, Me
3. Hg, Pb
4. Ld, My

Q. Identify the reactants in the following reaction.

$\text{KOH(aq)}+{\text{HNO}}_3\text{(aq)}\to {\text{H}}_2\text{O(l)}+{\text{KNO}}_3\text{(aq)}$

1. ${\text{H}}_2\text{O}$, ${\text{KNO}}_3$
2. $\text{KOH}$, ${\text{HNO}}_3$
3. ${\text{KNO}}_3$, $\text{KOH}$
4. ${\text{HNO}}_3$, ${\text{H}}_2\text{O}$

Q.

What is the formula for Calcium Bisulfate?

Q.

Acetylene is the first member of a family of hydrocarbons called alkynes.
$H-C\equiv C-H$

What is its empirical formula?

1. 

2. 

3. 

4. 

Q.

Which of the following considered as binary compound?

1. Ammonium sulfate

2. Hydrogen sulfide

3. Hydrogen sulfate

4. Ammonium sulfide

Q.

Solis state is indicated by the symbol(s).

1. True
2. False

Q.

Write true or false for the following statement:
"Water is an element."

1. True
2. False

Q.

What does the Fe symbol of iron stand for?

1. Ferni

2. Fergus

3. Fermi

4. Ferrum

Q.

Give the chemical symbols of five elements derived from Latin or German names.

Q. The correct name of the compound NaClO is ________.

1. Sodium chlorite
2. Sodium chlorate
3. Sodium hypochlorite
4. Sodium perchlorate

Q.

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

1. True

2. False

Q.

8. Complete the following sentences, filling in the blanks with suitable words and numbers.

$\mathrm{CaS}$ is a compound called _________ ________ . It is formed by the chemical combination of __________ and _________ . It represents one _________ of the compound. Each molecule of this solid contains one atom of ___________ combined with one ________ of sulphur.

Q. Identify the chemical name of the compound ${\text{CaBr}}_2$.

1. Calcium bromine
2. Calcium bromite
3. Calcium bromate
4. Calcium bromide

Q. (i) What is molar mass?
(ii) Calculate the molar mass of the following substances:
C₂H₂, HCl, HNO₃

Q.

Which of the following symbol does not represent a molecule?

1. H

2. He

3. P₄

4. O₂

Q.

Write true or false. Correct the false statement.

The chemical formulae of different compounds can be written easily if the symbols and the valencies of the elements are known.

1. True
2. False