We give 70 j as heat to a diatomic gas, which then expands at constant pressure. the gas molecules rotate but do not oscillate. by how much does the internal energy of the gas increase?

50 Joule

Explanation:

Diatomic gas

Q = Heat given = 70 J

n = number of moles

Cp = specific heat at constant pressure

ΔT = Change in temperature

R = Gas constant  

Change in energy

ΔE = Q-w

⇒ΔE = n(Cp)ΔT-nRΔT

As it is a diatomic gas Cp = (7/2)R

Putting the value of Cp in the above equation we get

Q = (7/2)RΔT

ΔE = (5/2)RΔT

Dividing the equations we get

ΔE/Q = 5/7

⇒ΔE = (5/7)Q

⇒ΔE = (5/7)×70

⇒ΔE = 50 J

∴ The internal energy change is 50 Joule

50

Explanation:

I took the test and got it right

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms