Question

1)the energy of the second Bohr orbit of the hydrogen atom is -3.41 eV. the energy of the second Bohr orbit of the HE^+ ion will be ____
a) -6.82 eV
b) -13.64eV
c) -1.70eV
d) -0.85eV

2) which mg alloy is used in making part of jet engines?
a) 3%Mish metal and 0.1%zr
b) 30%Mish metal and 0.1%zr
c) 30%Mish metal and 1%zr
d) 3%Mish metal and 1%zr

3) after 24 hr only 0.2 g out of the initial quantity of 1g of radio isotopes remains behind. what is the half life period?
a) 0.6690hr^-1
b) 0.76hr
c) 0.464hr^-1
d) 10.34hr

4) acetic acid is less than formic acid Because of ___
a) steric effect of -Ch3 group
b) +I effect of alkyl group
c) resonance effect of alkyl group
d) -I effect of alkyl group

5) when benzene diazonium chloride reacts with N, N-dimethyl aniline at ice cold condition gives____
a) p-amino azo benzene
b) Diazo amine benzene
c) p-Dimethyl amino azo benzene
d) p-methyl amino azo benzene

also ans the>> 9th question<<< assertion nd reason in the attached pic

plzz don't spam..
give the correct ans .... plzz
12th chemistry (stateboard)​

Answer 1

【H】【e】【y】

1. The energy of an electron in a Bohr atom is expressed as where, k = constant, Z = atomic number, N = orbit number E_n = - 〖kZ〗^2/n^2 = - 13.6 eV for H (n = 1) When n = 2, E2 = E_2 = (- 13.6)/2^2 eV = - 3.40 eV (n can have only integral value 1, 2, 3,……. ∞)

2. (b) 30%Mish metal and 0.1%zr

3. half life means time at which concentration becomes half

now,

1g------>0.5g---------->0.25g--------->0.125g

you see concentration continued half

if i let half life is t then 4t time take to cocentration become 0.125

hence , 4t=24 hr

t=6 hr

hence ,

half life =6 hR

4.

a) steric effect of -Ch3 group

5.

c) p-Dimethyl amino azo benzene

9. (b)A is True but R is False.

Answer 2

hola mate.!!

Answer:-

1:The energy of an electron in a Bohr atom is expressed as where, k = constant, Z = atomic number, N = orbit number E_n = - 〖kZ〗^2/n^2 = - 13.6 eV for H (n = 1) When n = 2, E2 = E_2 = (- 13.6)/2^2 eV = - 3.40 eV (n can have only integral value 1, 2, 3,……. ∞)

2. (b) 30%Mish metal and 0.1%zr

3. half life means time at which concentration becomes half

now,

1g------>0.5g---------->0.25g--------->0.125g

you see concentration continued half

if i let half life is t then 4t time take to cocentration become 0.125

hence , 4t=24 hr

t=6 hr

hence ,

half life =6 hR

4.

a) steric effect of -Ch3 group

5.

c) p-Dimethyl amino azo benzene

9. (b)A is True but R is False.

hope it helps...!!