There would be 0 Potential energy, which eliminates A. There would be Spring energy, which eliminates C. So B and D are your 2 choices. Since the child is not moving just before the jump, there would be 0 Kinetic energy. So D.
<span>1.86 moles of hydrogen gas.
Since what the HCl is reacting with hasn't been mentioned, I'll assume zine. In that case, the balanced reaction is
Zn + 2HCl ==> ZnCl2 + H2
So for every 2 moles of HCl used, 1 mole of hydrogen gas will be generated. So let's figure out how many moles of HCl we have and then divide by 2.
Molarity is defined as moles/liter. So a 2.75 M HCl solution has 2.75 moles of HCl per liter. So the total number of moles we have is:
2.75 mole/L * 1.35 L = 3.7125 mol
And since we get 1 mole H2 per mole of HCl, we get:
3.7125 mol / 2 = 1.85625 mol
Rounding to 3 significant figures gives us 1.86 moles of hydrogen gas.</span>
Answer:
2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.
Explanation:
Suppose x is the number of litres added to the 10% mixture than the quantity of new mixture is given as below
litres
litres
Also the quantity of alcohol is given as
Now the equation is as

So 2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.