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
Metal conductivity generally goes down or resistivity goes up with temperature goes up.
B. Most rocks are composed of single mineral
Boiling water is a physical change, because it is changing state of matter, there is a controllable temperature change, and you can change it back.
Frying the egg white is a chemical change, because there is a change of matter, controllable temperature change, but you CAN'T change it back.
