MCQ:

Q1 to Q10

DDDDBCBBDB

Section B

1a A

b "A and D" and "C and D"

c neutralisation

2a From colorless to pink

b Sodium hydroxide and hydrogen (NO shortforms allowed coz is NAME)

3a Red[Pink + Red+ colourless = Red] (no reddish pink) ( just copy down red can le)

b Blue

c (any ans between 7.8 - 8.3) ( ans CANNOT be a range)

4a) Aluminium, zinc, iron, tin, lead

b Gas is produced from chemical reaction

c) *Copy the whole chunk down* Dilute sulfuric acid is a strong acid while dilute ethanoic acis is a weak acid. Being a strong acis, there is a high concentration of hydrogen ions available in dilute sulfuric acid to react with the magnesium compared to the low concentration of hydrogen ions in dilute ethanoic acid. Therefore, the evolution of the product of the gas is fast in the case if dilute sulfuric acid, causing a vigorous effervescence, while that in a dilute ethanoic acid is slow, causing slow effervescence.

5) *copy whole chunk down* Mentions that it may not be an acid. And if it really is an acid, usage of alkali can produce alot of heat with acid, or excess alkali may be corrosive.

*continuation*

No. He is not sure of whether that is an acid. It maybe some other substance. He should wash his hand with a running tap and report the matter to his teacher. Moreover, even if he is right about the acid, neutralise acid with alkali will cause two problems:

1)the reaction will produce alot of heat and may burn his hand.

2)he may have added excess alkali to his hand and alkali may be corrosive.

Section C

1a) A strong acid is one whereby its molecules undergo complete dissociation in aqueous soution, forming a very rich concentration of H+ ions. A weak acid is one whereby its molecule undergo slight or partial dissociation in aqueous, forming a low concentration of H+ ions. Most of the weak acid remains as undissociated molecules.

b)Use the same concentration and volume of hydrochloric acid and enthanoic acid.

Transfer (5 cm3) hydrochloric acid in a test tube and (5 cm3) of ethanoic acid into another test tube, add equal mass of magnesium ribbon.

The test tube with hydrochloric acid will have a vigorous reaction and the reaction is much faster as compared to the test tube with enthanoic acid. This shoes that hydrochloric acid is a stronger acid than ethanoic acid.

Or

Using the same volume and concentration of hydrochloric acid and ethanoic acid, set up the diagram as shown below

The light bulb which is connected to hydrochloric acid will shine brighter than the one in ethanoic acid.

Or

Set up a circuit with batteries and wires, and pass electricity into a beaker with equal volume and concentration of each acid. Measure the conductivity with a voltmeter/ammeter for each acid. A higher reading is obtained for hydrochloric acid than ethanoic acid.

c) The litmus paper must be moist to allow ammonia gas to dissolve in the water and dissociate to form hydroxide ions.

*continue next lesson on Weds*

If nvr copy is ur prob liao

File all things and do all correction

the content page i will clarify wif mr xiong to see wad to write

*MUST bring file on Weds*

Spread to those u noe hu nvr go for lecture on last weds the...

edit those wrong spelling for urself

the section C if got Or means copy all dun copy just one part

- Plan the report on (new)Page 18 of sitwrite booklet

Chinese: - Jianbao

- Moxie (声声慢 and 一剪梅)

- 理解问答

Maths: - Assignment 11

- Worksheet 17d

Geog: - Assignment

- Worksheet

happy national day and happy holidays!

don't forget malay is due when school re-opens on wednesday !

MCQ:

Q1 to Q10

DDDDBCBBDB

Section B

1a A

b "A and D" and "C and D"

c neutralisation

2a From colorless to pink

b Sodium hydroxide and hydrogen (NO shortforms allowed coz is NAME)

3a Red[Pink + Red+ colourless = Red] (no reddish pink) ( just copy down red can le)

b Blue

c (any ans between 7.8 - 8.3) ( ans CANNOT be a range)

4a) Aluminium, zinc, iron, tin, lead

b Gas is produced from chemical reaction

c) *Copy the whole chunk down* Dilute sulfuric acid is a strong acid while dilute ethanoic acis is a weak acid. Being a strong acis, there is a high concentration of hydrogen ions available in dilute sulfuric acid to react with the magnesium compared to the low concentration of hydrogen ions in dilute ethanoic acid. Therefore, the evolution of the product of the gas is fast in the case if dilute sulfuric acid, causing a vigorous effervescence, while that in a dilute ethanoic acid is slow, causing slow effervescence.

5) *copy whole chunk down* Mentions that it may not be an acid. And if it really is an acid, usage of alkali can produce alot of heat with acid, or excess alkali may be corrosive.

*continuation*

No. He is not sure of whether that is an acid. It maybe some other substance. He should wash his hand with a running tap and report the matter to his teacher. Moreover, even if he is right about the acid, neutralise acid with alkali will cause two problems:

1)the reaction will produce alot of heat and may burn his hand.

2)he may have added excess alkali to his hand and alkali may be corrosive.

Section C

1a) A strong acid is one whereby its molecules undergo complete dissociation in aqueous soution, forming a very rich concentration of H+ ions. A weak acid is one whereby its molecule undergo slight or partial dissociation in aqueous, forming a low concentration of H+ ions. Most of the weak acid remains as undissociated molecules.

b)Use the same concentration and volume of hydrochloric acid and enthanoic acid.

Transfer (5 cm3) hydrochloric acid in a test tube and (5 cm3) of ethanoic acid into another test tube, add equal mass of magnesium ribbon.

The test tube with hydrochloric acid will have a vigorous reaction and the reaction is much faster as compared to the test tube with enthanoic acid. This shoes that hydrochloric acid is a stronger acid than ethanoic acid.

Or

Using the same volume and concentration of hydrochloric acid and ethanoic acid, set up the diagram as shown below

The light bulb which is connected to hydrochloric acid will shine brighter than the one in ethanoic acid.

Or

Set up a circuit with batteries and wires, and pass electricity into a beaker with equal volume and concentration of each acid. Measure the conductivity with a voltmeter/ammeter for each acid. A higher reading is obtained for hydrochloric acid than ethanoic acid.

c) The litmus paper must be moist to allow ammonia gas to dissolve in the water and dissociate to form hydroxide ions.

*continue next lesson on Weds*

If nvr copy is ur prob liao

File all things and do all correction

the content page i will clarify wif mr xiong to see wad to write

*MUST bring file on Weds*

Spread to those u noe hu nvr go for lecture on last weds the...

edit those wrong spelling for urself

the section C if got Or means copy all dun copy just one part

- Plan the report on (new)Page 18 of sitwrite booklet

Chinese: - Jianbao

- Moxie (声声慢 and 一剪梅)

- 理解问答

Maths: - Assignment 11

- Worksheet 17d

Geog: - Assignment

- Worksheet

happy national day and happy holidays!

don't forget malay is due when school re-opens on wednesday !