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[n] moles of an ideal gas with a molar heat capacity at constant volume of [cv] cal/(mol·K) and a molar heat capacity at constant pressure of [cp] cal/(mol·K) starts at [t1] K and is heated at constant pressure to [t2] K, then cooled at constant volume to its original temperature. How much heat (in calories) flows into the gas during this two-step process?  Enter only a numerical value with three significant figures, no units.

A sealed bag of potato chips contains [V1] L of air at sea level where the pressure is 1.00 atm (

A weather balloon contains [V1] m3 of hydrogen gas at a location at which the temperature is [T1]°C and the pressure is [p1] kPa. The balloon then rises to an altitude where the temperature is [T2]°C and the pressure is [p2] kPa. Assuming the balloon expands freely so that the gas pressure inside always equals the outside pressure, and the hydrogen is in thermal equilibrium with the air, what is the balloon’s new volume in cubic meter? Enter only a numerical value with three significant figures, no units.

Two samples of noble gases are compared: Sample A: 80 g of helium gas (He, molar mass = 4.0 g/mol) Sample B: 400 g of argon gas (Ar, molar mass = 40.0 g/mol) Which sample contains the greater number of moles of gas?

What is the electron configuration of Chromium (Cr)?

Which quantities are different between two species represented by the two notation and   ?     

Gallium (Ar = 69.72) consists of two stable isotopes, Ga-69 and Ga-71. What is the relative abundance of Ga-71?

What is the electron configuration of ?

[HL students only] Identify the relative atomic mass of element X, based on the mass spectrum provided below.

[HL students only] The frequency of the convergence limit for the hydrogen atom is  3.18 × 1015 s−1. Calculate the ionisation energy for hydrogen in kJ mol−1   (Planck’s constant, h = 6.63 x 10-34)