Which of the following solutions have the same number of hydrogen ions as in 50 cm3 of 0.1 mol dm-3 sulphuric acid?

I 100 cm3 of 0.1 mol dm-3 hydrochloric acid
II 50 cm3 of 0.2 mol dm-3 nitric acid
III 100 cm3 of 0.2 mol dm-3 sulphuric acid
IV 50 cm3 of 0.1 mol dm-3 phosphoric acid

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

the answer is yes

it has kinetic energy

reason

an object has kinetic energy when you stop the force carrying it, the object will stay in motion.

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