The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
The % yield if 500 g of sulfur trioxide reacted with excess water to produce 575 g of sulfuric acid is calculated using the below formula
% yield = actual yield/ theoretical yield x100
actual yield =575 grams
to calculate theoretical yield
find the moles of SO3 used =mass/molar mass
= 500g/ 80 g/mol =6.25 moles
SO3+H2O=H2SO4
by use of mole ratio of SO3 : H2SO4 which is 1:1 the moles of H2SO4 is also= 6.25 moles
the theoretical yield of H2SO4 is therefore = moles /molar mass
= 6.25 x98= 612.5 grams
%yield is therefore= 575 g/612 g x100= 93.9 %
Answer:
4.16g of MgCl2
Explanation:
First, let us generate a balanced equation for the reaction:
Mg + 2HCl —> MgCl2 + H2
Molar Mass of Mg = 24g/mol
Molar Mass of MgCl2 = 24 + (2x35.5) = 24 + 71 = 95g
From the equation,
24g of Mg produced 95g of MgCl2.
Therefore, 1.05g of Mg will produce = (1.05x95)/24 = 4.16g of MgCl2
There is an increase in the number of collisions between particles and the walls of the container<span>. b. There is an increase in the </span>temperature of the gas. If<span> the volume of a </span>container<span> of </span>gas<span> is reduced, what will </span>happen to the pressure inside<span> the </span>container
