Calculate the number of grams contained in each of the following number of moles. report your answer with the appropriate number of significant figures. a. 0.410 mol of nacl (sodium chloride) b. 4.80 mol of c2h4 (ethylene)

Answers:

a. 131.85 grams

b. 134.69 grams

To calculate the number of grams in the number of moles given for each compound, consider the formula:

Moles = No. of grams / molar mass

Therefore, to find the gram it will become:

No. of grams = moles x molar mass

a.  0.410 mol of NaCl (sodium chloride)

Molar mass of NaCl = (286.14 + 35.45) = 321.59

No. of grams = moles x molar mass

No. of grams = 0.410 x 321.59 = 131.85 grams

b. 4.80 mol of C2H4 (ethylene)

Molar mass of C2H4 = (12.01 x 2) + (1.01 x 4) = 28.06

No. of grams = moles x molar mass

No. of grams = 4.80 x 28.06 = 134.69 grams

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.