What is mass in g of 15.5 moles of calcium?

621.2090000000001 grams

Explanation:

1 moles Calcium to grams = 40.078 grams

15.5*40.078 = 621.2090000000001 g

44.6millilitres

Explanation:

Using the general gas law equation as follows:

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressure (atm)

V1 = initial volume (L)

T1 = initial temperature (K)

P2 = final pressure (atm)

V2 = final volume (L)

T2 = final temperature (K)

According to this question;

V1 = 30mL

T1 = 273K (STP)

P1 = 1 atm (STP)

V2 = ?

T2 = 300K

P2 = 75.0 kPa = 75 × 0.00987 = 0.74atm

Using P1V1/T1 = P2V2/T2

1 × 30/273 = 0.74×V2/300

30/273 = 0.74V2/300

Cross multiply

300 × 30 = 273 × 0.74V2

9000 = 202.02V2

V2 = 9000/202.02

V2 = 44.55

V2 = 44.6millilitres.