Compounds

Q.

What is law of multiple proportion ? Explain with an example clearly

Q.

The electronic configurations of three elements A, B and C are as follows:
$$\begin{array}{cc}A& 2,8,1\\ B& 2,8,7\\ C& 2,4\end{array}$$

(a) Which of these elements is a metal?
(b) which of these elements are non-metals?
(c) Which two elements will combine to form an ionic bond?
(d) Which tow elements will combine to form a covalent bond?
(e) Which element will form an anion of valency 1?

Q.

In a chemical substance the elements are always present in definite proportion by mass.

1. True

2. False

Q. Liquified or perfectly dried ammonia is neutral to litmus.

1. False
2. True

Q. Question 2
The ability of metals to be drawn into thin wire is known as
(a) ductility
(b) malleability
(c) sonorousity
(d) conductivity

Q.

The metals that produce sound on striking a hard surface are said to be:

1. Ductile

2. Sonorous

3. Lustours

4. Malleable

Q.

Question 43
A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.

Q.

The properties of a compound are_____ from those of its constituent elements. ​

Q.

Question 42
When a metal X is treated with cold water, it gives a base Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z, which easily catches fire. Identify X, Y and Z and also write the reaction involved.

Q. Question 47.
A sulphate salt of group 2 element of the periodic table is a white, soft substance, which can be moulded into different shapes by making its dough. When this compound is left in the open for some time, it becomes a solid mass and cannot be used for moulding purposes.
Identify the sulphate salt and why does it show such a behaviour ?
Write down the reaction involved.

Q. carbon and iodine are non metals. How, I think they are lustrous

Q.

Match the following:

$$\begin{array}{cccc}\text{(i)}& \text{Water}& \text{(A)}& \text{Compound}\\ \text{(ii)}& \text{Hydrogen}& \text{(B)}& \text{Element}\\ \text{(iii)}& \text{Salt}& & \\ \text{(iv)}& \text{Gold}& & \\ \text{(v)}& \text{Carbon dioxide}& & \\ \text{(vi)}& \text{Iron}& & \end{array}$$
The correct pairs are:-

1. (i, iii, iv) – A, (ii, v, vi) - B

2. (i, iii, v) – A, (ii, iv, vi) - B

3. (i, ii, iii) – A, (iv, v, vi) - B

4. (i, ii, v) – A, (iii, iv, vi) - B

Q.

Both silicon and carbon can form compounds with hydrogen. But the difference lies in their:

1. Size and valency
2. Valency and stability of compounds
3. Size and stability of compounds

Q.

In the law of constant proportion, the word constant means that the mass ratio of the elements in a chemical compound is same everywhere in the universe.

1. True

2. False

Q. Which of the following property is generally not shown by metals?
(a) Electrical conduction
(b) Sonorous in nature
(c) Dullness
(d) Ductility

Q. Is molecular formula and elemental formula of an element are different?If yes, then what is the difference.

Q. belongs to the sodium family of salts.

1. $KN{O}_3$
2. $NaHC{O}_3$
3. $KN{H}_2$

Q. Explain the terms.
a) Metallurgy (b) Ores (c) Minerals

Q. When an element of very low ionization potential reacts with an element of very high electron affinity, then :

1. a weak ionic bond is formed
2. a polar covalent bond is formed
3. a strong ionic bond is formed
4. no bond is formed

Q. How can sodium and chlorine help each other achieve the octet configuration?

Q.

Give the formulae fo the compound that would be formed by the ombinatiion of the ollowing pairs of elements:
(a) $Mgand{N}_2$ (b) $Liand{O}_2$ (c) $AlandC{l}_2$ (d) $KandH$

Q. Homogenous is a type of mixed substance and how compound is homogenous if it is , then give me the explaination of hetrogenous and homogenous mixture?

Q. In addition to sodium hydrogen carbonate, baking powder contains a substance $X$. Name the substance $X$

Q.

Define solution.

STATEMENT 1: A solution is a homogenous mixture of two or more substances.

STATEMENT 2: We can have solid solutions as alloys.

STATEMENT 3: A solution has homogeneity at the particle level.

STATEMENT 4: Lemonade is an example of a solution.

1. Statement 1 is true.

2. Statement 2 is true.

3. Statement 3 and 4 are true.

4. All are correct.

Q. Which of the following is an alkali metal?

1. Magnesium
2. Chlorine
3. Potassium
4. Calcium

Q. A carbonate ore is ________________.

1. carnallite
2. limonite
3. siderite
4. horn silver

Q. ________ are elements which can accept one or more electrons and form negative ions.

1. Metals
2. Metalloids
3. Non-metals
4. None of these

Q. One gram of a metallic chloride was found to contain $0.835g$ of chlorine. Its vapour density metallic chloride is $85.5$. If its molecular formula is $M_{x}C{l}_y$, then what is the value of $(x+y)$ ?

Q. can the constituent element of a compound be in any proportion of atom and mass

Q. Metals like copper and silver are refined by:

1. distillation
2. calcination
3. electrolytic refining
4. liquation