- Organic Chemistry
- Aldehydes and Ketones
- Alkyl Halides, Alcohols and ethers
- Amines and other nitrogen compounds
- Aromatic Chemistry
- Carbohydrates, Amino acids, protein, Vitamin and Fat
- Carboxylic acids and its derivatives
- Chemistry in daily life
- General Mechanism in organic compounds
- Hydrocarbons
- Nomenclature and isomerism
217 - Chemistry Questions Answers
1.0 ml of dilute solution of NaOH is added to 100 ml of a buffer of pH 4. The pH of the resulting solution
(a) becomes 7.0
(b) becomes 9.0
(c) becomes 3.0
(d) Remains practically unchanged
it is strong acidic buffer so answer is (d)
10 ml of M/200 H2SO4 is mixed with 40 ml of M/200 H2SO4. The ph of the resulting solution is
M of H2SO4 = 1/200
so [H+] = 2*1/200 = 1/100 = 10-2
now calculate pH
The pH of solution at 25°C which has twice as many hydroxide ion as in pure water at 25°C , will be
no of hydroxide ion in pure water = 10-7
so according to the given condition no. of hydroxide ions in solution = 2*10-7
so pOH = -log2*10-7
so pH = 14 - pOH
The ph of 0.1 M HCN is 5.2. What is the Ka?
HCN -------------------> H+ + CN-
0.1 0 0
0.1-x x x
pH = 5.2
so -log[H+] = 5.2
solve for [H+], it will give x
then calculate Ka
ΔHf C2H4 = 12.5 kcal
Heat of atomization of C = 171 kcal
Heat of atomization of H = 52.1 kcal
Bond energy C−H = 99.3 kcal .
What is C=C bond energy?
2 heat of atomization of C + 4 heat of atomization of H - 4 bond energy of C-H - 1 bond energy of C=C = heat of formation of C2H4
2*171 + 4*52.1 - 4*99.3 - x = 12.5
solve
How Is the value of n calculated for nerst equation??
n is the no. of electrons in anode or cathode reaction.
If no. of electrons are different then make these no. common
for ex. if reactions are
Al ---------------> Al+++ + 3e-
and Cu++ + 2e- ------------> Cu
then multiply (1) to 2 and (2) to 3
after that electrons will be 6 in both reactions so n = 6
which of the following has the maximum value for van der waals constant b - H2O (g) , AlCl3 (g), Cl2 (g)
b depends on size so on the basis of size order will be AlCl3>Cl2>H2O
This answer is given by Sarika and is correct answer
the type of interaction present between NO3- ion and I2 molecule is ion-dipole interactions or ion-induced dipole interactions.Explains the difference between the two also.
I2 is non polar molecule so it will be ion-induced dipole interactions
Arrange the following molecules in the increasing order of ionic characters,
LiF, K2O, N2, SO2, ClF3
N2, SO2, ClF3, K2O, LiF
N2, SO2, ClF3, K2O, LiF
This order is due to difference of electronegativity of atoms in a molecule
more difference more will be the ionic character
The ratio of positive charge on H- atom in HX to that in HY from the following data is
Dipole moment of HX = 1.14 D and HY = 0.38 D
Bond length of HX = 127pm and HY = 170pm
Options are - (i) 3:4 , (ii) 4:1 , (iii) 1:4
dipole moment = charge * bond length
now solve