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:
The time taken for the cross mark to disappear decreases steadily down the column.
Explanation:
Now if we look at the data provided, we will discover that the volume of the HCl was held constant while the volume of the thiosulphate was increased steadily and the volume of water decreased steadily.
Recall that a system is more concentrated when it contains less volume of water and more volume of reactants. Hence as the volume of water in the system is being reduced, the concentration of reactants is increased.
It has been established that an increase in the concentration of reactants lead to an increase in the rate of reaction. The disappearance of the cross shows the completion of the reaction between HCl and thiosulphate. The faster or slower the cross disappears, the faster or slower the rate of reaction.
Since increase in concentration of reactants increases the rate of reaction, it is observed that as the volume of the thiosulphate increases (reactant concentration increases) the cross disappears faster (rate of reactant increases). Hence as the volume of thiosulphate increases, it takes a shorter time for the cross to disappear. This implies that the time column in the table (refer to the question) will decrease steadily as the volume of thiosulphate increases.
Answer:
B) translucent
Explanation:
Light only partially passes through them.
B. Particles of metallic structure begin to vibrate faster as they absorb.
C. Metals have a larger number of freely moving electrons.
D. Metals have high densities.
Answer:
<u>»</u><u> </u><u>Similarities</u><u> </u><u>:</u>
☑ They both react by chemical means, to produce either an element or compound as the end product of the chemical reaction.
• Take an example of Magnesium reacting with cold water:
• If it reacts with steam:
• [ Element: <em>Magnesium</em><em> </em>and Compound: <em>Water</em><em> </em>]
They are both classified under atomic substances cause they are made up of microscopic molecules known as atoms.
☑ They are both formed up by microscopic substances known as atoms.
<u>»</u><u> </u><u>Differences</u><u> </u><u>:</u>
☑ Compounds generally have higher molecular masses than elements.
☑ Compounds are formed through bonding by elements while elements can naturally exist or formed by extraction, purification and concentration
