Answer:
C) It is the reactant that is left over after the reaction stops.
Explanation:
The excess reactant is the reactant that is left over after the reaction stops. The extent of the reaction is not determined by this reactant.
A limiting reactant is a reactant that is in short supply within a given reaction.
Such reactants determines the extent of chemical reaction.
- Limiting reactants are used up in a chemical reaction.
- The excess reactants remains unchanged after the reaction.
Answer: 2948
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = age of sample = ?
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 
Thus the fossil is 2948 years old.
Yes.
A covalent bond holds it together, which is chemical.
Answer:
19.5g is the theoretical yield of alum
Explanation:
Based on the balanced reaction, 4 moles of sulfuric acid produce 2 moles of alum. To solve this question we need to find the moles of H2SO4. With these moles we can find the moles of alum and its mass assuming all sulfuric acid reacts producing alum.
<em>Moles Sulfuric Acid:</em>
8.3mL = 0.0083L * (9.9mol/L) = 0.08217 moles sulfuric acid
<em>Moles Alum:</em>
0.08217 moles sulfuric acid * (2mol KAl(SO4)2•12H2O / 4mol H2SO4) =
0.041085 moles KAl(SO4)2•12H2O
<em>Mass Alum -Molar mass: 474.3884 g/mol-</em>
0.041085 moles KAl(SO4)2•12H2O * (474.3884 g/mol) =
<h3>19.5g is the theoretical yield of alum</h3>
The first order rate law has the form: -d[A]/dt = k[A] where, A refers to cyclopropane. We integrate this expression in order to arrive at an equation that expresses concentration as a function of time. After integration, the first order rate equation becomes:
ln [A] = -kt + ln [A]_o, where,
k is the rate constant
t is the time of the reaction
[A] is the concentration of the species at the given time
[A]_o is the initial concentration of the species
For this problem, we simply substitute the known values to the equation as in:
ln[A] = -(6.7 x 10⁻⁴ s⁻¹)(644 s) + ln (1.33 M)
We then determine that the final concentration of cyclopropane after 644 s is 0.86 M.
