I love these type of questions :)
Final Answer: Neon
The answer is 89.4 g/mol cuz the two units carry positives so that means 8.50 flows for 2 more hours than usual.
60.7 ml is the volume of a sample of CO2 at STP that has a volume of 75.0mL at 30.0°C and 91kPa.
Explanation:
Data given:
V1 = 75 ml
T1 = 30 Degrees or 273.15 + 30 = 303.15 K
P1 = 91 KPa
V2 =?
P2 = 1 atm or 101.3 KPa
T2 = 273.15 K
At STP the pressure is 1 atm and the temperature is 273.15 K
applying Gas Law:
= 
putting the values in the equation of Gas Law:
V2 = 
V2 = 
V2 = 60.7 ml
at STP the volume of carbon dioxide gas is 60.7 ml.
Molar mass:
HF = 1 + 19 = 20.0 g/mol
Number of moles :
124 / 20.0 => 6.2 moles
Volume = 2.4 L
M = n / V
M = 6.2 / 2.4
M = 2.6 M
Answer A
hope this helps!