Answer:
See explanation below
Step-by-step explanation:
According to the solubility curve attached, let's analyze each sentence to see which one is correct:
<u>"Solubility of NaCl is least affected by temperature"</u>
True. as you can see in the curve, solubility of NaCl remains almost constant at any value of temperature, so in this case, it does not matter the temperature, the NaCl solubility will be the same.
<u>"completely dissolve 60 g of KBr in 100 g of water at 20 °C"</u>
True. As you can see in the graph, solubility of KBr begins at 60 g, so in 20 °C we have something dissolved there. Actually you have like 70 g dissolved there, so, this is true.
<u>"The solubility of KNO3 is the least affected by changes in temperature"</u>
False. The curve for KNO3 is exponencial, so, changes in temperature do actually affect the solubility.
<u>"100 g of KBr will dissolve completely in 100 g of water at 75 °C"</u>
False. According to the curve, 100 g dissolve when we reach more than 100 °C. At 75 °C only about 85 g of KBr is dissolved.
<u>"if you mix 120 g of NaClO3 in 100 g of water at 10 °C, approximately 30 g will not dissolve"</u>
True. In the graph we can clearly see that at 10 °C only about 90 g is being dissolved so, the rest of the mass is still there as mass.
Option B:
The expression equivalent to |a| ≤ 5 is a ≥ -5 and a ≤ 5.
Solution:
Given expression:
To find the equivalent expression for the given expression.
Apply absolute value rule:
<em>If |x| ≤ m then -m ≤ x ≤ m.</em>
⇒ -5 ≤ a ≤ 5
⇒ -5 ≤ a and a ≤ 5
Switch the sides, we get
⇒ a ≥ -5 and a ≤ 5
The expression equivalent to |a| ≤ 5 is a ≥ -5 and a ≤ 5.
Option B is the correct answer.