  Problem solving tips

## Hydrogen

- Tricks and tips to solve difficult problems easily.
1
Calculation of Volume Strength of Hydrogen Peroxide
In this chapter, you can expect questions where you have to carry out calculations on volume strength of hydrogen peroxide. Hydrogen peroxide forms a hydrate when mixed in water. When solving questions related to strength of hydrogen peroxide, remember these points:
1. 'X' volume of 'Y%' hydrogen peroxide means that 1 millilitre of the solution will give 'X' mL of oxygen at STP. 1 litre solution will give 10 litre of oxygen. 1 ml solution will give 10 mL of oxygen.
2. Here's the chemical equation behind this decomposition: . According to this, 1 mole of = 2 moles of
3. At STP, one mole of oxygen occupies 22.7 litres.
4. Shortcut for molarity: If molarity of a solution is M, then its volume strength will be 11.2 X M.
5. Shortcut for normality: If normality of a solution is N, then its volume strength will be 5.6 X N.

Here's a question you can solve:
2
Calculations on Boiling and Freezing Points of Water
When it comes to questions on freezing and boiling points of water, you can expect questions where the units are not just in but also in and . So make sure you remember all of them! Try this question:
3
Resemblance of Hydrogen
Hydrogen has resemblance with both alkali metals and halogens. Here's what you need to remember about these similarities while answering related questions: Here are some questions you can try solving:
Hydrogen resembles halogen in many respects for which several factors are responsible. Of the following factors which one is the most important in this respect?
A
Its tendency to lose electron
B
Its tendency to gain electron in its valence shell
C
Its low negative electron gain enthalpy
D
Its small size
In what respect is the electronic configuration of hydrogen and halogens similar?
A
Hydrogen and halogens have one electron in their outermost shell
B
Hydrogen and halogens have one electron less than noble gas configuration
C
Hydrogen and halogens can lose one electron
D
Hydrogen and halogens show noble gas configuration