Question

interpreting indicators
ph range
evan tests the ph of a liquid using
cabbage juice and litmus. the
litmus is blue and the cabbage
juice is a lime green color.
what is the possible ph range of the
unknown substance based on the
experimental outcome?
ph indicator colors
1 2 3 4 5 6 7 8 9 10 11 12 13 14
phenolphthalein
litmus
cabbage juice
hydrion paper
1 2 3 4 5 6 7 8 9 10 11 12 13 14
greater than 13
greater than 7
between 9 - 13
less than 7

Explanation:

Step1: Analyze litmus indicator

Litmus is blue, which indicates a basic solution (pH > 7) since blue litmus is for bases (pH > 7, red litmus is for acids, pH < 7).

Step2: Analyze cabbage juice indicator

Cabbage juice is lime green. From the pH indicator colors, the lime green (or yellow - green) for cabbage juice corresponds to a pH range of 9 - 13 (looking at the cabbage juice row in the pH indicator table, the greenish - yellow color is in the 9 - 13 range).

Step3: Combine the information

Litmus blue (pH > 7) and cabbage juice lime green (pH 9 - 13). The overlapping and more precise range from both indicators is between 9 - 13. But wait, let's re - check. Wait, litmus blue is pH > 7 (blue litmus is basic, so pH > 7), cabbage juice lime green: looking at the cabbage juice row, the colors: orange (1 - 3), pink (4 - 5), purple (6 - 7), blue (8 - 9), green (10 - 13), yellow (14). Wait, maybe I misread. Wait the cabbage juice row: let's see the pH scale 1 - 14. The cabbage juice colors: orange (1 - 3), pink (4 - 5), purple (6 - 7), blue (8 - 9), green (10 - 13), yellow (14). So lime green would be in the 9 - 13? Wait no, blue is 8 - 9, green is 10 - 13, yellow is 14. Wait the problem says lime green. Maybe the lime green is in the 9 - 13? Wait litmus blue: litmus indicator, blue litmus is for bases (pH > 7), red litmus for acids (pH < 7). So litmus blue means pH > 7. Cabbage juice lime green: from the table, the cabbage juice's green - yellowish color is in the pH range of 9 - 13? Wait no, let's check the options. The options are greater than 13, greater than 7, between 9 - 13, less than 7. Litmus blue: pH > 7. Cabbage juice lime green: looking at the cabbage juice row, the green color (lime green) is in the pH range of 9 - 13? Wait the cabbage juice row: the colors are orange (1 - 3), pink (4 - 5), purple (6 - 7), blue (8 - 9), green (10 - 13), yellow (14). So if it's lime green, maybe around 9 - 13? But litmus blue is pH > 7. The most accurate range that fits both is between 9 - 13? Wait no, wait the litmus blue is pH > 7, and cabbage juice lime green (let's say the green is 9 - 13). So the possible pH range that satisfies both is between 9 - 13? But let's check the options. Wait the option "between 9 - 13" is one of the options. But wait, litmus blue is pH > 7, cabbage juice lime green (if green is 9 - 13), then the range is between 9 - 13. But let's re - evaluate. Wait, maybe I made a mistake in the cabbage juice color. Let's look at the litmus row: red (1 - 6), blue (7 - 14). Oh! Wait, I think I made a mistake earlier. Litmus: red litmus is for acids (pH < 7, red), blue litmus is for bases (pH > 7, blue). Wait the litmus row: the color red is from pH 1 - 6, blue is from pH 7 - 14. Oh! That's a key mistake. So litmus blue means pH ≥ 7 (or pH > 7, since at pH 7 it's neutral, but litmus is blue for basic, so pH > 7). Now cabbage juice: the cabbage juice row: orange (1 - 3), pink (4 - 5), purple (6 - 7), blue (8 - 9), green (10 - 13), yellow (14). So lime green would be in the green range (10 - 13) or blue - green? Wait, if litmus is blue (pH > 7) and cabbage juice is lime green (let's say green, which is 10 - 13), but litmus blue is pH 7 - 14. So the overlapping range from both indicators: litmus blue (pH > 7) and cabbage juice lime green (pH 9 - 13? Wait no, cabbage juice blue is 8 - 9, green is 10 - 13, yellow is 14. So if the cabbage juice is lime green, maybe 9 - 13? But litmus blue is pH > 7. The option "between 9 - 13" is more precise than "greater than 7" and "greater than 13" (since cabbage juice lime green is not indicating greater than 13, as yellow is 14) and "less than 7" is wrong (since litmus is blue, not red). Wait, but let's re - check the litmus row. The litmus row: the color red is from pH 1 - 6, blue is from pH 7 - 14. So litmus blue means pH ≥ 7. Cabbage juice lime green: looking at the cabbage juice row, the green color is in the pH range of 9 - 13 (since blue is 8 - 9, green is 10 - 13, yellow is 14). So the possible pH range that satisfies both litmus blue (pH ≥ 7) and cabbage juice lime green (pH 9 - 13) is between 9 - 13. But wait, the option "between 9 - 13" is correct? Wait no, maybe I messed up the litmus. Wait, blue litmus paper: blue litmus paper turns red in acid (pH < 7) and stays blue in base (pH > 7). Red litmus paper turns blue in base (pH > 7) and stays red in acid (pH < 7). Wait the problem says "the litmus is blue" – so if it's blue litmus, it's in a base (pH > 7). Now cabbage juice: the cabbage juice colors: let's see the pH scale. The cabbage juice row: pH 1 - 3: orange, 4 - 5: pink, 6 - 7: purple, 8 - 9: blue, 10 - 13: green, 14: yellow. So lime green would be in the 9 - 13? Wait 8 - 9 is blue, 10 - 13 is green, 14 is yellow. So lime green (a shade of green) would be in the 9 - 13 range? Wait 8 - 9 is blue, so 9 - 13 is green. So the cabbage juice lime green is in 9 - 13, and litmus blue is in pH > 7. So the intersection is 9 - 13. But wait, the option "between 9 - 13" is available. But let's check the options again:

Option 1: greater than 13 – cabbage juice would be yellow at 14, not lime green, so no.

Option 2: greater than 7 – litmus blue is pH > 7, but cabbage juice lime green is more precise (9 - 13), so "greater than 7" is too broad.

Option 3: between 9 - 13 – this fits both litmus blue (pH > 7) and cabbage juice lime green (9 - 13).

Option 4: less than 7 – litmus would be red, not blue, so no.

So the correct range is between 9 - 13. Wait, but wait the litmus row: if the litmus is blue, and the litmus row in the table: the litmus color is red from 1 - 6, blue from 7 - 14. So litmus blue means pH 7 - 14. Cabbage juice lime green: 9 - 13. So the overlapping range is 9 - 13.

Answer:

between 9 - 13