41.Sharna boiled some red cabbage in water. The cabbage-water turned purple.(a)(i)Sharna separated pieces of cabbage from the cabbage-water.Which method did she use?Tick the correct box.chromatographyfiltrationcondensationfreezing (ii)Sharna wanted to find out if the purple cabbage-water contained more than one coloured substance.Which method did she use?Tick the correct box.chromatographyfiltrationcondensationfreezing(b)Sharna mixed the purple cabbage-water with some other liquids.She wrote the colours of the mixtures in a table as shown below.colour of cabbage-watermixed with liquidIs the liquid acidic,alkaline or neutral?liquid 1redacidicliquid 2bluealkalineliquid 3purpleneutralUse the information in the table to answer parts (i) and (ii) below.(i)Sharna mixed cabbage-water with colourless washing-up liquid.The mixture turned blue.What does this tell you about the washing-up liquid?............................................................................................................... (ii)Sharna then mixed cabbage-water with lemon juice.Lemon juice is acidic.What colour was the mixture?............................................................. (c)What is the name of a chemical which changes colour when it is mixed with acids or alkalis?Tick the correct box.filtrateindicatornon-metalsolution2.The pH scale shown below is used to measure how acidic or alkaline a solution is.The graph below shows how the pH of the liquid in Barry's mouth changed as he ate a meal.(a)(i)Use the graph to give the pH of the liquid in Barry's mouth before he started to eat.pH ..................1 mark(ii)What does this pH tell you about the liquid in Barry's mouth before he started to eat? Use the pH scale above to help you.Tick the correct box.It was acidic.It was alkaline.It was colourless.It was neutral.1 mark(b)Look at the graph above.What happened to the pH of the liquid in Barry's mouth as he ate the meal?.....................................................................................................................1 mark(c)Barry chews special chewing gum after each meal. The chewing gum neutralises the liquid in his mouth.What type of substance neutralises an acid?Tick the correct box.an acidan alkalian indicatora solid3.Molly used a pH sensor to test different liquids. She dipped the probe of the sensor into each liquid and recorded the pH value in a table.(a)In the table below, tick one box for each liquid to show whether it is acidic, neutral or alkaline. One has been done for you.liquidpH valueacidicneutralalkalinealcohol7dilute hydrochloric acid2distilled water7vinegar3sodium hydroxide solution11(b)Between each test Molly dipped the probe into distilled water.(i)Why did she do this?...................................................................................................................................... (ii)Which other liquid in the table could Molly use between tests to have the same effect as distilled water?............................................................................................................. 4.Bees and wasps are both insects which use a sting as part of their defence.The pH values of their stings are shown on the diagrams. bee wasp bee sting, pH 2 wasp sting, pH 10(a)Complete the table below to show whether the stings are acidic or alkaline and what colour they would turn universal indicator paper. (b)The table below shows five household substances and the pH of each substance.name of substancepH of substancebicarbonate toothpaste8lemon juice3vinegar4washing soda11water7Give the name of one substance in the table which would neutralise each sting.(i)bee sting ............................................................................................. (ii)wasp sting ...........................................................................................Level 65.A scientist compared the acidity of four gases to see which gas might cause acid rain.She used four balloons to collect the gases.She then bubbled the gases, in turn, through a fresh sample of green, neutral,universal indicator solution.(a)Three of the gases caused the indicator to change colour.The scientist added drops of alkali to the indicator until the indicator changed back to green.Her results are shown in the table below.gasescollectedchange in colourof indicatornumber of dropsof alkali needed to changethe indicator back to greenexhaust gasesfrom a cargreen to red31carbon dioxidegreen to red160airno change0human breathgreen to yellow10Use information in the table to answer part (i) and part (ii) below.(i)Which gas dissolved to form the most acidic solution?...........................................................Explain your choice...........................................................................................................................................................................................................................1 mark(ii)Which gas formed a neutral solution?...........................................................Explain your choice...........................................................................................................................................................................................................................1 mark(iii)What effect does an alkali have on an acid?.............................................................................................................1 mark(b)Some metals react with acids in the air.Complete the word equation for the reaction between zinc and hydrochloric acid.zinc + hydrochloric ........................................ + ........................................ acid2 marksmaximum 5 marks