Answer:
the atomic number decreased in 2, from 100 to 100 - 2 = 98. 3) Hence the formed atom has atomic number 98, which is californium, Cf, and the isotope is californium - 253. 4) The item that completes the given alpha decay reaction is: ₉₈²⁵³ Cf.
Explanation:
The correct answer is C. Litmus Indicator
Pb(NO₃)₂ ⇒limiting reactant
moles PbI₂ = 1.36 x 10⁻³
% yield = 87.72%
<h3>Further explanation</h3>
Given
Reaction(unbalanced)
Pb(NO₃)₂(s) + NaI(aq) → PbI₂(s) + NaNO₃(aq)
Required
- moles of PbI₂
- Limiting reactant
- % yield
Solution
Balanced equation :
Pb(NO₃)₂(s) + 2NaI(aq) → PbI₂(s) + 2NaNO₃(aq)
mol Pb(NO₃)₂ :
= 0.45 : 331 g/mol
= 1.36 x 10⁻³
mol NaI :
= 250 ml x 0.25 M
= 0.0625
Limiting reactant (mol : coefficient)
Pb(NO₃)₂ : 1.36 x 10⁻³ : 1 = 1.36 x 10⁻³
NaI : 0.0625 : 2 = 0.03125
Pb(NO₃)₂ ⇒limiting reactant(smaller ratio)
moles PbI₂ = moles Pb(NO₃)₂ = 1.36 x 10⁻³(mol ratio 1 : 1)
Mass of PbI₂ :
= mol x MW
= 1.36 x 10⁻³ x 461,01 g/mol
= 0.627 g
% yield = 0.55/0.627 x 100% = 87.72%
Answer:
Constant pressure
Explanation:
At constant pressure,
At constant temperature,
1 mol of an ideal gas at STP has a volume of 22.71 L.
Let's compare the work done as it expands under each condition from an initial volume of 22.71 L.
Isobaric expansion
A plot of -w vs V₂ gives a straight line (red) with a constant slope of 100 J/L as in the diagram below (Note that w is work done on the system, so -w is the work done by the system).
\
Isothermal expansion
A plot of -w vs V₂ is a logarithmic curve. Its slope starts at 100 J/mol but decreases as the volume increases (the blue curve below).
Thus, the work done during an expansion at constant pressure is greater than if the system is at constant temperature.
D. The Moon is the Earth's largest natural satellite.
There you go!
