Chemistry Questions

Both Formaldehyde and Acetaldehyde will give this test

 HCHO→[Ag(NH3)2+] Silver mirrorAg + Organic compound

 CH3-CHO →[Ag(NH3)2+] AgSilver mirror+ Organic compound

F-F = 4 - 4 = 0

Ca-F = 4 - 1 = 3.0

H-F = 4 - 2.2 = 1.8

Na-F = 4 - 0.93 = 3.07

Hence, the highest electronegativity difference is in Na-F.

Given Equation is 

Mg + O2 → MgO

Balancing the Chemical Equation is nothing but Conservation of Matter. As Matter is Neither created nor Destroyed, it must be conserved.

Here we have 1 Mg and 2 O on the left side and 1 Mg and 1 O on the right side

To balance that, add 1 Mg on the left side so that it becomes 2 Mg and 2 O on the left side

i.e,

2 Mg + O2 → 2 MgO

Here it has 2 Mg & 2 O on the left side and 2 Mg and 2 O on the right side and the Chemical equation is Balanced.

A) Cooking of Food  ------ Chemical Change

B) Digestion of Food ----- Chemical Change

C) Freezing of water ----- Physical Change

D) Water is heated up ---- Physical Change

because here the chemical composition of the substance changes in A & B only.

Since we know that, If the chemical composition is changing then it is a chemical change and if the chemical composition is remaining the same, then it is a physical change.

3 – Hexanol:

There is no alcohol stretch present in the spectrum. Therefore, the above structure is not suitable for the given spectrum.

Trans – 4 – octene:

There is no vinyl bending present in the spectrum. Therefore, the above structure is not suitable for the given spectrum.

1, 5 – hexadiene:

The vinyl bending and other stretches were matched with the above structure.

Hence, the c = c stretch, vinyl bending and stretch were matched with the above structure.

Therefore, the given spectrum belongs to 1, 5 – hexadiene.

Equivalent conductance is defined as the conductance of an electrolyte solution containing one gram equivalent of the electrolyte. It is equal to the product of specific conductance (k) of the solution and the volume (V) of the solution that contains one gram equivalent of the electrolyte.

 λ = k x V

Unit of spceific conductance k is Siemens / m.

Volume of the solution V is m3

Now, required equivalent conductance unit is Siemens.m2/equivalent.

In hydrocarbon, the boiling point directly varies with the length of carbon chain. On increasing the number of carbon atom, the boiling point of the compound also increases. Paraffin contains highest number of carbon atoms whereas, ethane is comprised of two carbon atoms.

The decreasing order of boiling point of mention compounds is written as follows:

Paraffin > Octadecane > Hexane > Neohexane > Ethane