Welcome to your CHM TEST MBBS
1.
We know that most of an atom’s mass is in its nucleus; the mass of an electron compared to mass of the lightest nucleus is ___
2.
What is the mole fraction of sodium hydroxide in a 20% by mass, solution of sodium hydroxide?
3.
The oil drop experiment by R.A. Millikan was performed to find________.
4.
Rutherford carried out experiments in which a beam of alpha particles was directed at a thin piece of metal foil. From these experiments he concluded that:
5.
Calculate the molarity of a solution after 1.70liters of 2.06M solution is diluted to 2.50liters?
6.
The maximum number of electrons that can be accommodated in a sublevel for which "ml" = ±1 and 0 is
7.
An Oil drop has 6.39×10^−19C change. Find out the number of electrons in this oil drop.
8.
How many significant figures are in 100.0
9.
Y = A + B - C. If A = 5.79 ± 0.03, B = 15.19 ± 0.02 and C = 21.609 ± 0.004. Calculate the standard error in Y
10.
Which of the solution is the most concentrated?
11.
A hypothetical element with an atomic weight of 65.0 amu consists of just two isotopes. One of the isotopes consists of atoms having a mass of 64.23 amu; the other of 65.32 amu. What is the percent natural abundance of the heavier isotope?
12.
Calculate the de-Broglie's wavelength if an electron travels at the speed of light. (Given that Planck's constant, h is 6.626 × 10-³⁴Js)
13.
In 1932, the neutron was discovered by a scientist by bombarding beryllium with radiation. What is the name of the scientist and what radiation did he bombard beryllium with?
14.
What is the molality of a 20% by mass, solution of sodium hydroxide?
15.
What is the percentage yield of water if 0.95g of water is obtained when 29.0g of butane is burned in excess oxygen?
16.
When an electron do transition from n = 4 to n=2, the emitted line of spectrum will be:
17.
Nuclides with the same atomic mass are called
18.
A compound has a composition of 40% Sulphur and 60% Oxygen by mass. What is the empirical formula of this compound? ( S=32, O=16))
19.
According to Milikan, electronegativity is defined as
20.
How many grams of NaOH are needed to prepare 125mL of 0.2M solution of NaOH?