Answer:
KI 1.0 M
Explanation:
Freezing point of a substance is a colligative property. This means that it depends on the amount of substance present is the system.
The freezing point is given by; T - Ta = K * m * i
Where;
T = freezing point of the pure solution
Ta = freezing point of the solution containing the solute
K = freezing point constant
m = molality of the solution
i= Van't Hoff factor
If we look at all the options provided, KI has only two particles in solution and a molality of 1.0 m hence it should exhibit the lowest freezing point of solution.
Answer: The mass is 348.8g
Explanation:
We begin by using Avogadro's number to convert the number of molecules of Sodium Hydroxide to moles.
6.02 x 10∧23 molecules of NaOH -------> 1 mole of NaOH
∴ 5.25 x 10∧24 molecules of NaOH -------> 1/ 6.02 x 10∧23 x 5.25 x 10∧24 =
8.72moles.
Having found the number of moles, we then move from moles to gram by using the molar mass of NaOH (i.e the mass of 1 mole of NaOH).
1 mole of NaOH is equivalent to 40g (Molar Mass)
8.72 moles of NaOH would be equivalent to; 40/ 1 x 8.72 = 348.8g
The mass in 5.25 x 10∧24molecules of NaOH is 348.8g
Transition metals are metals found in the middle of the periodic table. The answer is Pb.
Answer:
See Explanation
Explanation:
The way by which a metal is obtained from its ore is determined by the chemical reactivity of the metal.
Metals that are highly reactive are chiefly obtained by electrolysis of the metal salt. These metals are found high up in the metal activity series.
Metals that are at the middle of the series are moderately reactive and are obtained by electrolysis or by reduction since they still form ionic salts.
Metals that are far lower in the series can only be obtained by heating them in air because they are mostly unreactive.
Hence, moderately reactive metals at the middle of the series are not obtained by roasting in air.
