Answer:
There is 54.29 % sample left after 12.6 days
Explanation:
Step 1: Data given
Half life time = 14.3 days
Time left = 12.6 days
Suppose the original amount is 100.00 grams
Step 2: Calculate the percentage left
X = 100 / 2^n
⇒ with X = The amount of sample after 12.6 days
⇒ with n = (time passed / half-life time) = (12.6/14.3)
X = 100 / 2^(12.6/14.3)
X = 54.29
There is 54.29 % sample left after 12.6 days
Answer:
– 1
Explanation:
From the question given above, we obtained the following:
Electron = 8
Net charge of nitrogen =.?
Nitrogen has atomic number of 7. This also means that nitrogen has 7 proton because atomic number of an element is the equal to number of protons in the atom of the element.
Thus, we can obtain the net charge of nitrogen with 8 electrons by calculating the difference between the protons and electrons of the nitrogen atom. This can be obtained as follow:
Proton = 7
Electron = 8
Net charge = Proton – Electron
Net charge = 7 – 8
Net charge = – 1
Therefore, the net charge of the nitrogen atom with 8 electrons is – 1
Answer:
148.04 kJ/mol
Explanation:
Let's consider the following thermochemical equation.
NO(g) + 1/2 O₂(g) → NO₂(g) ΔH°rxn = -114.14 kJ/mol
We can find the standard enthalpy of formation (ΔH°f) of NO(g) using the following expression.
ΔH°rxn = 1 mol × ΔH°f(NO₂(g)) - 1 mol × ΔH°f(NO(g)) - 1/2 mol × ΔH°f(O₂(g))
ΔH°f(NO(g)) = 1 mol × ΔH°f(NO₂(g)) - ΔH°rxn - 1/2 mol × ΔH°f(O₂(g)) / 1 mol
ΔH°f(NO(g)) = 1 mol × 33.90 kJ/mol - (-114.14 kJ) - 1/2 mol × 0 kJ/mol / 1 mol
ΔH°f(NO(g)) = 148.04 kJ/mol
Answer:
u will equate and make V2 the subject because it's the one u are looking for ....
