Core 1- Calculations

Question 1

What are the standard temperature and pressure for calculating volumes of a gas?

Answer 1

273K and 1.01x10^5 Pa

Question 2

What is the molar volume of a gas under STP?

Answer 2

22.4 dm3

Question 3

Which of the following is an empirical formula?
C2H6
NH3
C6H6
C6H12O6

Answer 3

NH3

Question 4

What is the empirical formula of a substance containing 0.34g C, 0.057g H and 0.46g O?

Answer 4

CH2O

Question 5

Give the ideal gas equation

Answer 5

PV = nRT

Question 6

What volume will 0.27mol of a gas occupy at 300K and atmospheric pressure?

Answer 6

6.66x10^-3 m3

Question 7

How many cm3 in 1m3?

Answer 7

1x10^6

Question 8

25.0cm3 of 0.100M NaOH neutralises 19.8cm3 HCl- find the concentration of HCl

Answer 8

0.126M

Question 9

What is the concentration of 4g NaOH dissolved in 250 cm3 water?

Answer 9

0.025M

Question 10

How many moles of oyxgen are there in 500cm3 of the gas at 25C and 100 kPa?

Answer 10

0.0200 mol

Question 11

What is the value for R, including units?

Answer 11

8.31 J/K/mol

Question 12

4.0g sodium hydroxide was reacted with 32.5g hydrochloric acid. Which reagent is defined as rate limiting and why?

Answer 12

The HCl is rate limiting as there is not enough of it for the NaOH to fully react with

Question 13

How many atoms of sodium hydroxide are there in 250cm(3) of a 0.5M solution?

Answer 13

(0.125 x 6x10^23)