Mole=mass/molecular mass (Mr)
mole=volume/ 22.4
Molecular amount: Mole=amount atoms/ Avogadro's number
Concentration: mole=volume x M
Answer:
2 x 2 = 4
Explanation:
Multiplication is just doubling the numbers depending on what you have. 3 x 3 = 9 because 3 three times is 9. Therefore, 2 two times is 4.
Answer:
There are 6 atoms
Explanation:
2 from the subscript and multiply it by 3 cause of the coefficient.
Answer:
What will happen to Uk if you double the mass?
Explanation:
Uk = 0.5 * m * v²
You see that both m and v are variable, which means that both m and v can be any number. Regardless of the numbers you put in for m or v, the formula to calculate the kinetic energy (Uk) remains valid.
You could ask
1. What will happen to Uk if you double the mass?
2. What will happen to Uk if you double the velocity?
please see and understand(!) that the relationship between Uk an v² is indeed the velocity squared....
EXTRA
Uk = 0.5 * m * (v)²
Suppose the m = 3kg and velocity = 5 m/s
What is the Uk?
Well if you know the formula you can use your calculator to find out:
Uk = 0.5 * m * (v)²
Uk = 0.5 * 3 * (5)²
Uk = 0.5 * 3 * 25
Uk = 37.5 kgm/s²
Again you ask what will happen to Uk if you double the velocity?
At first it was 5 m/s and now it doubles, which means it now has that value *2
The new velocity is 5 *2 = 10 m/s
Uk = 0.5 * m * (v)²
Uk = 0.5 * 3 * (10)²
Uk = 0.5 * 3 * 100
Uk = 150 kgm/s²
150 = 4 * 37.5
So now you see that if you double your velocity, the Uk will be 2² = 4 times as big !
Given question is incomplete. The complete question is as follows.
Pentaborane (
) is a colorless highly reactive liquid that will burst into flames when exposed to oxygen.the reaction is:
Calculate the kilojoules of heat released per gram of the compound reacted with oxygen.the standard enthalpy of formation
,
, and
are 73.2, -1271.94, and -285.83 kJ/mol, respectively.
Explanation:
As the given reaction is as follows.
Therefore, formula to calculate the heat energy released is as follows.

Hence, putting the given values into the above formula is as follows.

= 
= -9078.59 kJ/mol
Since, 2 moles of Pentaborane reacts with oxygen. Therefore, heat of reaction for 2 moles of Pentaborane is calculated as follows.
= -71.915 kJ/g
Thus, we can conclude that heat released per gram of the compound reacted with oxygen is 71.915 kJ/g.