Damp litmus paper is used to test for chlorine gas.
Which statement describes the correct result of the test for chlorine gas?
Damp blue litmus paper turns red then white.
Damp blue litmus paper turns white then red.
Damp red litmus paper turns blue then white.
Damp red litmus paper turns white then blue.
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A student adds sodium hydroxide solution to a small sample of copper(II) chloride solution.
A precipitate is made.
What is the colour of the precipitate?
Blue
Green
Orange
White
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Which statement about a mass spectrum of a molecule is correct?
Each peak represents an atom in the molecule.
The charge to mass ratio of the molecular ion peak is equal to the relative formula mass of the molecule.
The peak with the highest relative abundance represents the molecular ion.
The peak on the far right of the spectrum represents the molecular ion.
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During the electrolysis of brine, chlorine gas forms at one electrode.
2Cl- (aq) format('truetype')%3Bfont-weight%3Anormal%3Bfont-style%3Anormal%3B%7D%3C%2Fstyle%3E%3C%2Fdefs%3E%3Ctext%20font-family%3D%22math12bba9f4124283edd644799e0ce%22%20font-size%3D%2216%22%20text-anchor%3D%22middle%22%20x%3D%2210.5%22%20y%3D%2216%22%3E%26%23x2192%3B%3C%2Ftext%3E%3C%2Fsvg%3E)
Cl2 (g) + 2e-
Which test would be most appropriate to confirm that chlorine gas was produced?
Collect the gas and see if it extinguishes a glowing splint
Collect the gas and check if it is green
Collect the gas and see if it bleaches damp litmus paper
Collect the gas and check if it smells of swimming pools
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Which is the correct method for testing for hydrogen gas?
Hold the tube containing the gas upright and place a lit splint at the end of the tube
Hold the tube containing the gas upright and place a glowing splint at the end of the tube
Hold the tube containing the gas angled down and place a lit splint at the end of the tube
Hold the tube containing the gas angled down and place a glowing splint at the end of the tube
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Which is not true about the test for carbon dioxide gas?
The gas is bubbled through limewater solution
Limewater is calcium hydroxide solution
The solution will turn cloudy due to the formation of a white precipitate
The colour will fade after a few minutes
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What is the correct observation when a glowing splint is held at the entrance of a tube of pure oxygen gas?
A 'squeaky pop' sound can be heard
The glowing splint relights
The glowing splint keeps glowing
The glowing splint is immediately extinguished
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The electrolysis of fresh water produces hydrogen gas and oxygen gas.
The electrolysis of salt water (brine) produces hydrogen gas and chlorine, and leaves a solution of sodium hydroxide.
Which test would not help to identify a sample as being fresh water or salt water?
A gas collected makes a 'squeaky pop' when a lit splint is held in it
A gas collected relights a glowing splint
A gas collected bleaches damp litmus paper
The pH of the solution increases
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Scientists test a solution of compound X.
Table 1 shows their results.
Table 1
| Test | Result |
| Add dilute nitric acid followed by silver nitrate solution | White precipitate |
| Add sodium hydroxide solution | Green precipitate |
Which two ions are present in compound X?
Fe3+ and Cl-
Fe3+ and SO42-
Fe2+ and Cl-
Fe2+ and SO42-
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Scientists test a solution from a bottle that is known to contain a copper (II) compound.
Table 1 shows their results.
Table 1
| Test | Result |
| Flame test | Yellow flame |
| Add sodium hydroxide solution | Blue precipitate formed |
| Add dilute nitric acid followed by silver nitrate solution | Yellow precipitate formed |
Which statement below is true?
The flame test was performed incorrectly
Bromide ions are present, so the compound is CuBr2
The test tube was contaminated for the sodium hydroxide test
The copper compound in the bottle was contaminated with another metal compound
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A compound is suspected of containing calcium ions, Ca2+.
Which test would not help to positively identify calcium?
| Test | Result | |
| A | Flame test | Orange-red flame |
| B | Add sodium hydroxide solution | White precipitate forms |
| C | Add nitric acid and silver nitrate | White precipitate forms |
| D | Flame photometry | Characteristic lines match the reference spectrum |
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Which is not an advantage of using instrumental methods rather than small-scale lab methods for identifying ions?
Instrumental methods are more accurate
Instrumental methods are faster
Instrumental methods are cheaper
Instrumental methods are more sensitive
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Calcium carbonate can react with hydrochloric acid by the following equation:
CaCO3 (s) + HCl (aq) CaCl2 (aq) + H2O (l) + CO2 (g)
Which observation does not tell you that this reaction has occurred?
| Test | Result | |
| A | Add dilute nitric acid then by silver nitrate solution | White precipitate forms |
| B | Bubble any gases present through limewater | Limewater turns cloudy |
| C | Observe the solutions when they are mixed | Solutions bubble and fizz upon mixing |
| D | Test pH of the solution at the start and after 30 s | pH increases |
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Which element is present in this flame emission spectrum?
Reference line emission spectra chart
Helium
Mercury
Hydrogen
Neon
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Look at the mass spectrum of a carbon compound.
Which carbon compound is this mass spectrum from?
C4H10+
C3H5O2+
C3H8O
C4H8
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A student adds a few drops of sodium hydroxide solution to an unknown solution and a blue precipitate is made.
Which metal ion is present in the original solution?
Calcium
Copper(II)
Iron(II)
Iron(III)
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The table shows the stages in a flame test.
| Stage | Process |
| 1 | Dip a nichrome wire loop into the test solution |
| 2 | Observe and record the flame colour |
| 3 | Clean a nichrome wire loop with hydrochloric acid, then rinse with distilled water |
| 4 | Hold the nichrome wire loop in the edge of a roaring blue flame |
Which is the correct order for the stages in a flame test?
1, 4, 2, 3
1, 4, 3, 2
3, 1, 4, 2
3, 4, 1, 2
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Which statement describes the test for chlorine gas?
A lighted splint makes a squeaky pop.
Limewater turns milky.
A glowing splint re-lights.
Damp litmus paper is bleached.
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A student is testing sodium carbonate solution.
She adds barium chloride solution followed by excess dilute hydrochloric acid.
Which of these observations would not be seen?
Colourless solution at the end
Gas bubbles when the dilute acid is added
White precipitate formed when the barium chloride solution is added
White precipitate formed when the dilute acid is added
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Look at the mass spectrum of a carbon compound.
Which carbon compound is the mass spectrum from?
C2H2
C2H5+
C3H7+
C4H10
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Which statement describes the advantages of instrumental methods of analysis?
Instruments can analyse very small amounts and carry out the analyses slowly.
Instruments are very accurate and use large amounts of substances.
Instruments are very accurate and carry out the analyses slowly.
Instruments are very accurate and can run all the time.
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Which statement about a mass spectrum of a molecule is correct?
Each peak represents an atom in the molecule.
The charge to mass ratio of the molecular ion peak is equal to the relative formula mass of the molecule.
The peak with the highest relative abundance represents the molecular ion.
The peak on the far right of the spectrum represents the molecular ion.
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A student tests a solution for chloride ions.
She adds dilute nitric acid to the solution. She then adds a few drops of silver nitrate solution.
Why does she need to add dilute nitric acid in this test?
To increase the pH of the solution.
Nitrate ions are needed for the test to work.
To make sure that no carbonate ions are present.
The test only works in alkaline conditions.
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