0.091 moles are contained in 2.0 L of N2 at standard temperature and pressure.
Explanation:
Data given:
volume of the nitrogen gas = 2 litres
Standard temperature = 273 K
Standard pressure = 1 atm
number of moles =?
R (gas constant) = 0.08201 L atm/mole K
Assuming nitrogen to be an ideal gas at STP, we will use Ideal Gas law
PV = nRT
rearranging the equation to calculate number of moles:
PV = nRT
n = 
putting the values in the equation:
n = 
n = 0.091 moles
0.091 moles of nitrogen gas is contained in a container at STP.
The balanced reaction is:
<span>4Cr(s)+3O2 (g )= Cr2O3 (s)
Since we are not given the amount of any of the reactants, we assume we have one gram of chromium. Calculations are as follows:
1 g Cr ( 1 mol Cr / 52 g Cr ) ( 1 mol Cr2O3 / 4 mol Cr ) = <span>0.005 mol Cr2O3
</span></span>0.005 mol Cr2O3 (151.99 g Cr2O3 / 1 mol Cr2O3 ) = 0.7307 g <span>Cr2O3
</span>
Therefore, the theoretical yield for 1 gram of Cr is 0.005 mol Cr2O3 or 0.7307 g Cr2O3.
Answer : The activation energy for the reaction is, 119.7 J
Explanation :
According to the Arrhenius equation,
or,
![\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%20R%7D%5B%5Cfrac%7B1%7D%7BT_1%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
where,
= rate constant at 271 K
= rate constant at 281 K = 
= activation energy for the reaction = ?
R = gas constant = 8.314 J/mole.K
= initial temperature = 271 K
= final temperature = 281 K
Now put all the given values in this formula, we get:
![\log (\frac{2K_1}{K_1})=\frac{Ea}{2.303\times 8.314J/mole.K}[\frac{1}{271K}-\frac{1}{281K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7B2K_1%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B271K%7D-%5Cfrac%7B1%7D%7B281K%7D%5D)
Therefore, the activation energy for the reaction is, 119.7 J
<h3>
Answer:</h3>
5.89%
<h3>
Explanation:</h3>
We are given;
- Mass of the solute, LiOH as 40.1 g
- Mass of the solvent, H₂O as 681 g
We are required to calculate the mass percent composition of solution;
- But; How do we calculate the mass percent composition of a solution?
- We use the formula;
- Mass composition of a solution = (Mass of solute/mass of solution) 100%
Mass Percent = (40.1 g/681 g)× 100%
= 5.888 %
= 5.89%
Therefore, the mass percent composition of the solution is 5.89%
The number of Protons.
(which is also the ATOMIC NUMBER)
