Hardness = 75ppm = 75 mg / L
volume = 50 mL = 0.05 L
So, applying hardness formula:
Hardness = mass / volume
so, mass = hardness x volume = 75 x 0.05 = 3.75 mg = 0.00375 g
So, moles of CaCO3 = moles of Ca2+ ions = mass / molar mass of CaCO3 = 0.00375 / 100.06 = 0.00003747751 moles
I remember coming across this question and the options were:
KOH, HCN, NH₃, HI, Sr(OH)₂
Now, a substance with a low pH is one that dissociates completely in water to release hydrogen ions, while basic substances dissociate completely to release hydroxide ions. Therefore, in the order of increasing pH:
HI, HCN, NH₃, Sr(OH)₂, KOH
Answer:
c. Energy from the liquid is exhausted into the atmosphere outside the freezer
Explanation:
Energy from the liquid is exhausted into the atmosphere outside the freezer.
a. is wrong. If the energy remained inside the freezer, the warm liquid would cool down and the inside of the freezer would warm up.
b. is wrong. The freezer removes energy from the liquid.
Answer: A precipitate is formed as a result of a double displacement reaction.
