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How do you balance chemical equations?

Example question: _H 2 O --> _O 2 + _H 2 First, work out how many of each element you have on each side. For example in this equation, Left: 2 hydrogen and 1 oxygen Right: 2 hydrogen and 2 oxygen We can t...
EW
Answered by Eve W. • Science tutor
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Which chamber of the human heart pumps blood towards the lungs?

The right ventricle pumps blood towards the human heart.
AW
Answered by Alice W. • Science tutor
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The mass of a balloon is 0.02g before it is filled with air. After it is blown up with air the mass is 0.04g. Assuming oxygen makes up 21% of air, calculate the number of moles of oxygen in the balloon.

Mass of oxygen in balloon = 0.02 x 0.21 Mr (O2) = 16 x 2 = 32 Moles = mass / Mr = (0.02 x 0.21) / 32 = 1.31 x 10^4 moles Or 0.000131 moles
AW
Answered by Alice W. • Science tutor
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What is produced when Hydrochloric acid reacts with sodium

The general formula for when a acid reacts with a salt (sodium) is that a salt and hydrogen is produced. This should be learnt off by heart! So, our acid is Hydrochloric acid, and when this reacts to produce...
JL
Answered by Jas L. • Science tutor
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What are the stages of the Carbon Cycle? How are fossil fuels affecting CO2 levels?

Stage one: Carbon enters the atmosphere by - respiration in organisms (e.g. animals breathing) - combustion (e.g. burning of fossil fuels/ wood) - decomposition and decay (microorganisms respiration) Stage t...
RA
Answered by Rebecca A. • Science tutor
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