Chemistry

8.0g of copper oxide is reduced to 5.6g of copper using hydrogen gas. [relative atomic mass: Cu=64, O=16]
CuO + H2 → Cu + H2O
What is the yield of copper as a percentage of the theoretical maximum?

Which of the following statements are correct about the solvent properties of water?
1. All ionic substances dissolve in water.
2. All covalent substances are insoluble in water.
3. The solubility of solids usually increases with a rise in temperature.

Which one of the following is NOT correct about Fe, Cu and Zn, which are in the first row of the  transition metals?

In the following reactions, which substances are acting as oxidising agents?

Which rows of the table correctly describe the reactions of the aqueous acids with amines and amides?

Which one of the following is NOT the correct formula for a lithium compound?

Which name of the following phase changes is NOT correct?

Which of the following shows how the atomic radius of the elements changes on crossing from left to right in the row of the Periodic Table from potassium to bromine?

Which one of the following compounds can be made from ethanol using only a substitution reaction?

How many nitrogen electrons are involved in bond formation in HONO2 ?

Which of the following must be correct about organic isomers?
1. They have the same molecular formulae.
2. Their physical properties are very similar.
3. They have different structural formulae.

What is the total number of electrons in the ions of sodium chloride?