55 kg of liquefied natural gas (lng) are stored in a rigid, sealed 0.17 m3 vessel. in this problem, model lng as 100% methane. due to a failure in the cooling/insulation system, the temperature increases to 200 k, which is above the critical temperature; thus, the natural gas will no longer be in the liquid phase.

I am assuming that the problem ask for the pressure in the system. To be able to calculate this, we first assume that the system acts like an ideal gas, then we can use the ideal gas equation to find for pressure P.

P V = n R T

where,

P = Pressure (unknown)

V = 0.17 m^3

n = moles of lng / methane

R = gas constant = 8.314 Pa m^3 / mol K

T = 200 K

We find for the moles of lng. Molar mass of methane = 16 kg / kmol

n = 55 kg / 16 kg / kmol

n = 3.44 kmol CH4 = 3440 mol

Substituting all the values to the ideal gas equation:

P = 3440 mol * (8.314 Pa m^3 / mol K) * 200 K / 0.17 m^3

P = 33,647,247 Pa

P = 33.6 MPa

- 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