Q1.
You're right. The ans should be A not C.
Q2.
Regard this as a simple logic-type question, ie. knowledge
of content of 4 options not required; in other words, assuming
the info stated by each of the options is true, which option is
logically inconsistent? D, because if the reduction of iron ore to
iron is exothermic and takes place near the top, then logically the
top should be warmer, not cooler.
Q3.
Increasing the temperature does not change
the activation energy required for the reaction; instead what
happens is increasing the temperature increases the percentage of
reactant molecules whose energy equals or exceeds
the activation energy required for the reaction, and
therefore the rate of reaction increases.
1) Substance Q, upon addition of aq NH3 forms a white ppt which
is insoluble in excess. Besides, upon addition of dilute HNO3
and aq AGNO3, a white ppt is formed. What is Q?
A) Aluminium chloride B)Aluminium sulfate C)Lead(II) chloride
D)Lead(II) sulfate
Ans is C but i wanna know why A is not possible.
2) Which of the following statements cannot explain why the
temperature at the bottom of the furnace for extracting iron is
higher than the temp at the top?
A)Combustion of coke is an exothermic process which occurs where
hot air enters at the btm of the furnace
B)Decomposition of limestone is an endothermic process which
occurs where it is fed in at the top of the furnace
C)Hot air is fed in at the btm of the furnace is at a higher
temp than the waste gases leaving frm the top of the furnace
D) Reduction of iron ore to iron is an exothermic process which
occurs where the iron ore is fed in at the top of the furnace
Ans is D but i would also be interested to know how do A to C
explain the question.
3)What effect does a higher temp have on its activation energy
and enthalpy change?
EA
Enthalpy change
A
decreases
increases
B
decreases
no change
C no
change
increases
D no
change
no change
Ans is D but would like to know why its not B
