OCR Module 2

Welcome to your OCR Module 2

Three isotopes of a newly discovered element X are 117-X (relative abundance 3), 119-X (relative abundance 5), and 121-X (relative abundance 7). What is the relative atomic mass of element X?
The atomic mass of the ion of an element A+ is 23 and it has 10 electrons. How many protons, neutrons and electrons are present in the neutral atom A?
What is the concentration of the solution when 16g of sodium chloride is dissolved in 250 cubic centimetres of water?
Calculate the mass of nitrogen gas that has a pressure of 100 kPa, a temperature of 25 degrees centigrade, and a volume of 500 cubic centimetres (R = 8.31).
How many atoms of magnesium are present in an 18g sample of magnesium metal?
Which of the following conclusions can be made if percentage uncertainty due to apparatus is less than the percentage difference between the actual value and the calculated value?
Which of the following is the definition of a Bronsted-Lowry acid?
The oxidation number of carbon in carbonate ion is?
All uncombined elements have an oxidation number of what?
Iron reacts with hydrochloric acid to form iron(II)chloride and hydrogen gas. Which of the following is true about iron in this reaction?
What is the correct order of energies of subshells?
How many orbitals are there is the d subshell?
What type of bonding exists in ammonium chloride (NH4Cl)?
What is the bond angle in chlorine trifluoride (ClF3) is approximately equal to?
Which of the following statements is correct?
I. Polar molecules are symmetrical
II. Non-polar molecules can contain polar bonds
III. Van der Waals forces occur due to temporary dipoles