<u>Answer:</u> The correct answer is Option 4.
<u>Explanation:</u>
Bromothymol blue, Bromocresol green and Thymol blue are the indicators which change their color according to the change in pH of the solution.
The pH range and color change of these indicators are:
- Bromothymol Blue: The pH range for this indicator is 6.0 to 7.5 and color change is from yellow to blue. It appears yellow below pH 6.0 and blue above pH 7.5
- Bromocresol green: The pH range for this indicator is 3.5 to 6.0 and color change is from yellow to blue. It appears yellow below pH 3.5 and blue above pH 6.0
- Thymol Blue: The pH range for this indicator is 8.0 to 9.6 and color change is from yellow to blue. It appears yellow below pH 8.0 and blue above pH 9.6
As, the highest pH of all the indicators is 9.6, so every indicator will appear blue above pH 9.6.
Hence, the correct answer is Option 4.
Answer:
<u>Heating water with an open flame</u>
<u>Explanation:</u>
Remember, we are told in the label that Acetone is a "flammable liquid and vapor." <em>Being flammable means the substance can easily be set on fire</em>, and we would expect an open flame from heating water to trigger an explosion (a disaster) in which the Acetone is set on fire causing life-threatening dangers to the second group of students.
Answer:
a. Sn or Si ⇒ Sn
b. Br or Ga ⇒ Ga
c. Sn or Bi ⇒ similar in size
d. Se or Sn ⇒ Sn
Explanation:
The larger atom has a larger atomic radius. We have to consider how varies the atomic radius for chemical elements in the Periodic Table. In a group (column), the atomic radius increases from top to bottom while in a period (file), it increases from right to left.
a. Sn or Si ⇒ Sn
They are in the <u>same group</u>. Sn is on the top, so it has a larger atomic radius.
b. Br or Ga ⇒ Ga
They are in the <u>same period</u>. Ga is located at the left so it has a larger atomic radius.
c. Sn or Bi ⇒ similar
They are not in the same group neither the same period. Bi is located more at the bottom, so it would be larger than Sn, but Bi is also at the right side, so it would be smaller than Bi. Thus, they have comparable sizes.
d. Se or Sn⇒ Sn
They are not in the same group neither the same period. Se is located at the top and right side compared to Sn, so Sn is the larger atom.
