Explanation:
Hi for this one u just need to remember and use the equation.

then u find mr of potassium which is 39.1.
then u do

you get the answer as 0.5115 write ur answer to 3 significant figures which will be 0.512 moles .
hope this helps :)
Answer:
1670 ml
Explanation:
molarity x Volume (Liters) = moles => Volume (Liters) = moles/Molarity
Volume needed = 2.50mol/1.50M = 1.67 Liters = 1670 ml.
Answer:

Explanation:
Hello!
In this case, since the energy implied in a heating process is computed by using the following equation:

Whereas m is the mass, C the specific heat and T the temperature. In such a way, by plugging in the given mass, specific heat and temperatures, we obtain the following energy:

Considering that the specific heat can by used by unit of °C or K because their difference is equivalent.
Regards!