<span>C. New substances are always produced in chemical changes, which is not the case with physical changes. For example, when you cut wood into smaller pieces you still have wood in the end. But, with a chemical change you change the substance's whole composition. For example when you add two hydrogen's to one oxygen you have water and it can't break down from that. </span><span />
Answer:
No
Explanation:
Let us examine this problem carefully:
Given compound is N₂O
Molecular mass = 88g
Now,
The empirical formula is the simplest formula of a compound.
The molecular formula is the true formula of the compound that shows that actual ratios of the atoms in a compound.
To find if they both have the same molecular and empirical formula, they must have the same molecular mass.
For N₂O;
Molecular mass = 2(14) + 16 = 44g/mole
But the true and given molecular formula of the compound is 88g/mole
This shows that the compound given is the empirical formula of the compound.
Molecular formula:
molecular mass of empirical formula x n = molecular mass of molecular formula
n =
= 2
Molecular formula of compound = 2(N₂O) = N₄O₂
Therefore the empirical and molecular formulas are not the same
<u>Answer:</u> The half life of the sample of silver-112 is 3.303 hours.
<u>Explanation:</u>
All radioactive decay processes undergoes first order reaction.
To calculate the rate constant for first order reaction, we use the integrated rate law equation for first order, which is:
![k=\frac{2.303}{t}\log \frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%20%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken = 1.52 hrs
= Initial concentration of reactant = 100 g
[A] = Concentration of reactant left after time 't' = [100 - 27.3] = 72.7 g
Putting values in above equation, we get:

To calculate the half life period of first order reaction, we use the equation:

where,
= half life period of first order reaction = ?
k = rate constant = 
Putting values in above equation, we get:

Hence, the half life of the sample of silver-112 is 3.303 hours.
Answer:

Explanation:
Data:
I = 2.15 A
t = 8 min 24 s
T = 26.0 °C
V = 65.4 mL
p = 774.2 To
1. Write the equation for the half-reaction
2H₂O ⟶ O₂ + 4H⁺ + 4e⁻
2. Calculate the moles of oxygen
V = 0.0654 L
T = (26.0 + 273.15) K = 299.15 K

3. Calculate the moles of electrons

4. Calculate the number of coulombs
t = 8 min 24 s =504 s
Q = It = 504 s × 2.10 C·s⁻¹= 1058 C
5. Calculate the number of electrons

6. Calculate Avogadro's number
