Kinetic Energy= 0.5 times velocity squared times mass
So KE= 0.5times 150 times 40 squared
(Use a calculator)
And don't forget units
Thus problem is providing us with the mass of iron (III) oxide as 12.4 g so the moles are required and found to be 0.0776 mol after the calculations:
<h3>Mole-mass relationships:</h3>
In chemistry, we use mole-mass relationships in order to calculate grams from moles and vice versa. In this case, since we are given the mass of iron (III) oxide as 12.4 g one can calculate the moles by firstly quantifying its molar mass:

Then, we prepare a conversion factor in order to cancel out the grams and thus, get moles:

Learn more about mole-mass relationships: brainly.com/question/18311376
Hey there!
Al + HCl → H₂ + AlCl₃
Balance Cl.
1 on the left, 3 on the right. Add a coefficient of 3 in front of HCl.
Al + 3HCl → H₂ + AlCl₃
Balance H.
3 on the left, 2 on the right. We have to start by multiplying everything else by 2.
2Al + 3HCl → 2H₂ + 2AlCl₃
Now we have 2 on the right and 4 on the left. Change the coefficient in front of HCl from 3 to 4.
2Al + 4HCl → 2H₂ + 2AlCl₃
Now, for Cl, we have 4 on the left and 6 on the right. Change the coefficient in front of HCl again from 4 to 6.
2Al + 6HCl → 2H₂ + 2AlCl₃
Now, our H is unbalanced again. 6 on the left, 4 on the right. Change the coefficient in front of H₂ from 2 to 3.
2Al + 6HCl → 3H₂ + 2AlCl₃
Balance Al.
2 on the left, 2 on the right. Already balanced.
Here is our final balanced equation:
2Al + 6HCl → 3H₂ + 2AlCl₃
Hope this helps!
It's a weak base bacause H C N is weak