The percent yield for this reaction is 91%.
<u>Explanation</u>:
Ba(NO3)2 + Na2SO4 — > BaSO4 + 2NaNO3
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Assume that 0.45 mol of Ba(NO3)2 reacts with excess Na2SO4 to create 0.41 mol of BaSO4.
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Convert to grams of BaSO4 utilizing its molar mass (233.38 g/mol), which will be giving the actual yield.
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Actual Yield = 0.41 mol BaSO4 x (233.38 g BaSO4/1 mol BaSO4)
= 96 g BaSO4
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Beginning with 0.45 mol of Ba(NO3)2, compute the theoretical yield of BaSO4. Mole proportion of Ba(NO3)2 to BaSO4 is 1:1.
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0.45 mol Ba(NO3)2 x (1 mol BaSO4/1 mol Ba(NO3)2) x (233.38 g BaSO4/1 mol BaSO4) = 105 g BaSO4
% Yield = (Actual Yield/Theoretical Yield) x 100%
= (96/105) x 100%
= 91%.
Answer:
A white dwarf is what stars like the Sun become after they have exhausted their nuclear fuel. Near the end of its nuclear burning stage, this type of star expels most of its outer material, creating a planetary nebula. Only the hot core of the star remains. ... That means a white dwarf is 200,000 times as dense.
Explanation:
they are cold
they are about the size of Earth
these both are not true
The two particles that account for the mass of an atom are protons and neutrons. Electrons on the other hand are negligible mass, and so light they are considered without weight.
From the ideal gas law, PV = nRT, we can rearrange the equation to solve for T given the other parameters.
T = PV/nR
where P = 0.878 atm, V = 1.20 L, n = 0.0470 moles, and R = 0.082057 L•atm/mol•K. Plugging in our values, we obtain the temperature in Kelvin:
T = (0.878 atm)(1.20 L)/(0.0470 mol)(0.082057 L•atm/mol•K)
T = 273 K
So, the second answer choice would be correct.
Answer:
4.97 X 10^13 ATOMS OF Zn
Explanation:
how many atoms of zinc are required to weigh 5.4 ng
a nano gram is 10^-9 grams
Zinc has an atomic mass of 65.39 gm/moles
there is an Avogadros number of atoms in a mole
65.39 GRAMS PER MOLE
65.39 g/(6.022 X 10^23)how many atoms of zinc are required to weigh 5.4 ng
GRAMS PER ATOM
1.086 GRAMS PER 1O^22 ATOMS
1 atom of Zn weighs 1.086 X 10^9 X 1O^-22 n grm=
1,086 X 10^-13 n gm
Y tines 1.086 X 10^-13 = 5.4 n gm
Y = 5.4/ (1.086 X 10^-13) =
4.97 X 10^13 ATOMS OF Zn
CHECK
(4.97 X 10^13 ) X 65.39 gm/(6.022 X 10^23) =
5.397 X 10^-9 =
5.4 n g