Q: Tincal contains mainly :

Tincal mainly contains \$Na_2B_4O_7\cdot 10H_2O\$. It is borax or sodium tetraborate or sodium borate.

Question 1

Tincal contains mainly :

Accepted Answer

Tincal mainly contains $Na_2B_4O_7\cdot 10H_2O$. It is borax or sodium tetraborate or sodium borate.

Question 2

Which element has the highest valency with respect to oxygen?

Accepted Answer

The valence of an element with respect to oxygen is twice the number of oxygen atoms with which one atom of that element chemically combines.The valency of chlorine with respect to oxygen is 7.

Question 3

Which of the following is representative group of elements in the periodic table?

Accepted Answer

The elements present in s and p block elements except noble gases are known as representative elements .A) Lanthanum is in d block B) Argon is a noble gas C) Chromium is a d block elementD) Aluminium is a p block element Thus, aluminium is a representative element.Hence, option D is correct.

Question 4

Which element show more pronounced inert pair effect?

Accepted Answer

Inert pair effect is the reluctance of the outermost s-electrons to participate in bonding. This effect increases down the group.

Question 5

The monomer units of silicons, a water repellant, acid resistant and heat resistant polymer, is:

Accepted Answer

Alkyl group is water repellent and acid as well as heat resistant because of high bond energy. Hence, the monomer units of silicones as water repellant, acid-resistant and heat resistant polymer is $R_2Si(OH)_2$.Therefore, option C is correct.

Question 6

Non-metals present in borax are:

Accepted Answer

Borax is sodium tetraborate or sodium borate. Its formula is $Na_2B_4O_7\cdot 10H_2O$. It contains $O$ and $B$ non metals.

Question 7

Silicon is an important constituent of:

Accepted Answer

Chlorophyll has magnesium as an important metal, haemoglobin has iron as its important constituent, amalgams are mixtures of something with mercury. Note that, silicon is the second most abundant element in earth's crust.

Question 8

The element whose atomic volume is least is

Accepted Answer

In moving from left to right in a period the atomic volume first decreases and then incrases because-As we move left to right in a period , one electron and one proton gets added .Initially , the increase in nuclear charge overcomes the increase in the no. of electrons. Hence the atomic volume decreases.But in the right of the priodic table newly added electrons goes into the p orbital and due to high shielding power of s and p orbitals , atomic volume increase.Atomic volume of Boron is least

Question 9

The least abundant element of IV A group is :

Accepted Answer

The least abundant element of IV A group is Ge.The decreasing order of abundance is $Si > C > Sn > Pb > Ge$

Question 10

If the valency shell electronic structure for an element is $ns^{2} np^5$, this element will belong to the group of:

Accepted Answer

The valence shell or orbital electronic configuration of halogens(17th group elements) is $ns^2\  np^5$.Hence, the correct option is $\text{D}$

Some P Block Elements

Chemistry
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Tincal contains mainly :

Which element has the highest valency with respect to oxygen?

Which of the following is representative group of elements in the periodic table?

Which element show more pronounced inert pair effect?

The monomer units of silicons, a water repellant, acid resistant and heat resistant polymer, is:

Non-metals present in borax are:

Silicon is an important constituent of:

The element whose atomic volume is least is

The least abundant element of IV A group is :

If the valency shell electronic structure for an element is $n s^{2} n p^{5}$ , this element will belong to the group of:

Some P Block Elements

Chemistry 2678 Views

Tincal contains mainly :

Which element has the highest valency with respect to oxygen?

Which of the following is representative group of elements in the periodic table?

Which element show more pronounced inert pair effect?

The monomer units of silicons, a water repellant, acid resistant and heat resistant polymer, is:

Non-metals present in borax are:

Silicon is an important constituent of:

The element whose atomic volume is least is

The least abundant element of IV A group is :

If the valency shell electronic structure for an element is ns2np5, this element will belong to the group of:

Chemistry
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If the valency shell electronic structure for an element is $n s^{2} n p^{5}$ , this element will belong to the group of: