Chemistry MCQ thread...

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Q15- Electronegativity increases across the period and so does first ionisation energy ( since atomic size decreases as nuclear charge increases)
So if you check the data booklet Mg has a higher first ionisation energy than Al so answer is B. :)
thank uuu (y)
 
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A chemist took 2.00dm3 of nitrogen gas, measured under room conditions, and reacted it with a large volume of hydrogen gas, in order to produce ammonia. Only 15.0% of the nitrogen gas reacted to produce ammonia. What mass of ammonia was formed?
A 0.213g
B 0.425g
C 1.42g
D 2.83g

pleaseee helpp :(urgentt!!!!
 
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A chemist took 2.00dm3 of nitrogen gas, measured under room conditions, and reacted it with a large volume of hydrogen gas, in order to produce ammonia. Only 15.0% of the nitrogen gas reacted to produce ammonia. What mass of ammonia was formed?
A 0.213g
B 0.425g
C 1.42g
D 2.83g

pleaseee helpp :(urgentt!!!!
Is the answer o.425

if it is then first find the moles of nitrogen gas then take 15% of the moles
then take mole ratio with ammonia produced that would be 1:2
then you can use the formula n=m/Mr to find the mass of ammonia produced
 
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Is the answer o.425

if it is then first find the moles of nitrogen gas then take 15% of the moles
then take mole ratio with ammonia produced that would be 1:2
then you can use the formula n=m/Mr to find the mass of ammonia produced
yes it is dear, thank u so much
 
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In China, the concentration of blood glucose, C6H12O6, is measured in mmol / l . In Pakistan, the concentration of blood glucose is measured in mg/ dl. The unit l is a litre (1dm3 ). The unit dl is a decilitre (0.1dm^3 ).
A blood glucose concentration of 18.5mmol/l indicates a health problem.
What is 18.5mmol/l converted to mg/ dl?
A 33.3mg/ dl
B 178mg/ dl
C 333mg/ dl
D 3330mg/ dl

answer is C

PLEASE HELPP:D
 
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Is the answer o.425

if it is then first find the moles of nitrogen gas then take 15% of the moles
then take mole ratio with ammonia produced that would be 1:2
then you can use the formula n=m/Mr to find the mass of ammonia produced
YES IT IS
THANKS!
 
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9701_w13_qp_11 Q.3, 7, 11 plss.
Question 3: first step to do is to balance the second equation with the first equation with equal electrons. Combine both the two equations and you will get B.

Question 7: Answer is B because it is the reverse of homolytic fission of chlorine, which means it will release energy and no energy need for it to happen.

Question 11:

Using the equation : mass of water x specific heat capacity x change in temperature = heat released
=(150-50) x 4.18 x (53-20) = 13794 J
This is the heat produced by the burning of methanol to the water.
 
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When solid ammonium chloride dissociates at a certain temperature in a 0.500dm3 container, ammonia and hydrogen chloride are formed. NH4Cl(s) NH3(g) + HCl(g) The initial amount of ammonium chloride was 1.00mol, and when the system had reached equilibrium there was 0.300mol of ammonium chloride. What is the numerical value of Kc for this reaction under these conditions?
A 0.490 B 1.63 C 1.96 D 3.27
can u show me how to sove it??
 
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