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Bases and acids

hi, I'm currently doing Nat 5 and I'm stuck at these questions,
Which of the following gases reacts with water to produce an
alkaline solution?

A nitrogen dioxide
B ammonia
C oxygen
D argon
Which of the following substances dissolves in water to give a
solution of pH greater than 7?

A ammonia
B carbon dioxide
C sulphur dioxide
D sodium chloride

Question 3

A
H2O
B
NO2
C
K2O

D
CaO
E
CO
F
SO2

a) Identify the oxide produced by the sparking of air in car engines. 1

b) Identify the two oxides that dissolve in water to produce
alkaline solutions. 1

c) Identify two oxides produced by burning hydrocarbons. 1
(3)

132. When hydrogen chloride gas is dissolved in water a solution
containing hydrogen ions and chloride ions is formed.
Which equation correctly shows the state symbols for this change?

A HCl(g) + H2O( )  H+(aq) + Cl-(aq)
B HCl( ) + H2O(aq)  H+( ) + Cl-( )
C HCl(aq) + H2O( )  H+(aq) + Cl-(aq)
D HCl(g) + H2O( )  H+( ) + Cl-( )

thank you in advance for the help

Hi again KyleH123,

Hope you are well!

Answer is A -
NH3 dissoves in water to produce ammoinium hydroxide, which is alkaline:-

NH3 + H2O = NH4OH

Q3. a) Answer E: The four stroke engine (original version of car engine) produces carbon monoxide (CO) which is why you should not stay for long in a closed space (eg garage with engine running (CO is poisonous as it combines irreversibly with haemoglobin therefore interfering with oxygen delivery to respiring cells)

b) Answer C and D: CaO and K2O (oxides of metals [those that do react with or dissolve in water) produce alkaline solutions (oxides of non-metals generally produce acid solutions e.g. SO2 gives sulphurous acid (H2SO3) and SO3 (sulphur trioxide) gives sulphuric acid (H2SO4))

c) Hydrocarbons as the name tells you are made of hydrogen (H) and carbon (C) atoms; so burning them will produce oxides of C and H. ANSWER: A and E.

LAST Q: 132??

Answer A.

Depending waht stage of your course you are at and how far you are from your exams, my advice, KyleH123, is to start doing some solid work, perhaps drastically modifying your style of studying and revising, and getting a good tutor or some help from a more informed classmate/friend. The concepts herein are basic facts, without knowing and understanding which you are going to struggle in your exams. I am happy to help out as I have done, but my concern is that I might be doing you a disfavour by doing so, in that you are not learning to think and work out things for yourself.

Sorry if this sounds a bit blunt, but it is my honest well-meaning opinion.

Good luck!

Reply 3

KyleH123

Original post by macpatelgh

this was for a different user @macpatelgh

I have made changes since I requested help last time, and I am feeling a bit more confident. I am early on in my course yet so I have time to improve.

Thanks for your help.