Answer:
B. 0.92 M
Explanation:
Molarity of a solution = number of moles (n) ÷ volume (V)
According to the information provided in this question;
mass of NaCl = 42g
Volume of water = 780mL
Using mole = mass/molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
mole = 42/58.5
mole (n) = 0.72mol
Volume (V) = 780 mL = 780/1000 = 0.780 L
Hence, molarity = n/V
Molarity = 0.72/0.780
Molarity = 0.923 M
B is the correct answer tbh
Answer:
0.464 L
Explanation:
Molarity (M) = number moles (n) ÷ volume (V)
According to the information given in this question:
number of moles (n) = 4.36 moles
Molarity = 9.4M
Volume = ?
Using M = n/V
9.4 = 4.36/V
9.4V = 4.36
V = 4.36/9.4
V = 0.464 L
Hence, 0.464L of water are needed the volume of water.
Answer:
Copper turns green on exposure to air
Explanation:
Liquid water freezes to form ice: Physical change
Reason: Water can melt back when it becomes ice.
Copper turns green on exposure to air: Chemical change
Reason: The copper can not change back from the green state when it turns green.
Agriculture, space exploration, and also for medical purposes.
Hope I helped :)
