Chlorine gas turns damp starch-iodide paper
pink
colourless
red
dark blue
Correct answer is D
Chlorine turns a damp starch iodide paper into dark blue or blue black.
N2O4(g)→ 2NO2(g)
In the endothermic reaction above, more products formed will be favored by
A constant values
an increase in pressure
a decrease pressure
a decrease volume
Correct answer is C
A decrease in pressure will result in the breaking or splitting of a larger molecule into a simpler ones. Options A, B, D are not in conformance to the reaction
what is the pH of 0.00lmoldm3 solution of sodium hydroxide
14
13
12
11
Correct answer is D
[H+][OH−] = 10 − 4
[H+] =10 − 14 ÷ [OH+]
=10 −14 ÷ (1 × 10 − 3) = 10 − 11
pH = − log10[H+ ]
= − log10[10 − 11] = − 1 × −11
log10[10 − 11] = 1
= − 1 × 11 × 1
= − 11
Which of the following compounds can be represented by the molecular formula C2 H6O?
propanal
ethanol
methanoic acid
glucose
Correct answer is B
Ethanol has the molecular formula C2H6O. Option A, C, D are not because their molecular are not different
If glucose is heated with concentrated tetraoxosulphate(vi)acid, it will be dehydrated to?
carbon
carbon(iv)oxide
ethane
ethanol
Correct answer is A
Carbon concentration of 4 will not give a precipitate heating. Option B,C,D will not be dehydrated