<u>Answer:</u> The amount of white phosphorus is 0.0199 moles
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
We are given:
Given mass of white phosphorus = 2.478 g
Molar mass of white phosphorus = 124 g/mol
Putting values in above equation, we get:
Hence, the amount of white phosphorus is 0.0199 moles
Answer:
A = 679.2955 ppm
Explanation:
In this case, we already know that 64Cu has a half life of 12.7 hours. The expression to use to calculate the remaining solution is:
A = A₀ e^-kt
This is the expression to use. We have time, A₀, but we do not have k. This value is calculated with the following expression:
k = ln2 / t₁/₂
Replacing the given data we have:
k = ln2 / 12.7
k = 0.0546
Now, let's get the concentration of Cu:
A = 845 e^(-0.0546*4)
A = 845 e^(-0.2183)
A = 845 * 0.8039
A = 679.2955 ppm
This would be the concentration after 4 hours
Answer:
C₂H₇F₂P
Explanation:
Given parameters:
Composition by mass:
C = 24%
H = 7%
F = 38%
P = 31%
Unknown:
Empirical formula of compound;
Solution :
The empirical formula is the simplest formula of a compound. To solve for this, follow the process below;
C H F P
% composition
by mass 24 7 38 31
Molar mass 12 1 19 31
Number of
moles 24/12 7/1 38/19 31/31
2 7 2 1
Dividing
by the
smallest 2/1 7/1 2/1 1/1
2 7 2 1
Empirical formula C₂H₇F₂P
Answer:
She will observe that the pressure on the tire is higher.
Explanation:
By the ideal gas law, the pressure and the temperature are directly proportional, so, if the temperature increases the pressure increases too:
PV = nRT (P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature).
The temperature is a measure of the average kinetic energy of the gas molecules, so when the temperature increases, the energy also increases, and the gas molecules will move more quickly, so they will collide more often between themselves and in the wall. Those collisions will be with more force because the velocity is higher.
So, the pressure will be higher, because it is the result of collisions of the gas molecules with the walls of the tire.
To be able to answer this equations, we must set given information. Suppose the reaction to yield NO is:
N₂ + O₂ → 2 NO
Next, suppose you have 1 g of each of the reactants. Determine first which is the limiting reactant.
1 g N₂ (1 mol N₂/ 28 g)(2 mol NO/1 mol N₂)= 0.07154 mol NO present
Number of molecules = 0.07154 mol NO(6.022×10²³ molecules/mol)
<em>Number of molecules = 4.3×10²² molecules NO present</em>
