Answer:
(A) 15.0 °C
Explanation:
The water in beaker A gains heat because its initial temperature (10 °C) is less than the initial temperature of the water in beaker B (20 °C) which loses heat.
Let T3 be the final temperature
Heat gained by beaker A = heat loss by beaker B
mc(T3 - T1) = mc(T2 - T3)
The mass and specific heat of water in both beakers are the same. Therefore, (T3 - T1) = (T2 - T3)
T1 is initial temperature of beaker A = 10 °C
T2 is initial temperature of beaker B = 20 °C
T3 - 10 = 20 - T3
T3 + T3 = 20 + 10
2T3 = 30
T3 = 30/2 = 15 °C
To determine the heat required in order to decompose a certain amount of a substance, we need information on the heat needed to decompose one mole of the substance. This value are readily available online and other sources. For this reaction, the heat needed is 129 kJ per 2 mol of NaHCO3. We calculate as follows:
129 KJ / 2 mol NaHCO3 (1 mol / 84.01 g ) (25.5 g NaHCO3 ) = 19.58 kJ of heat is needed.
Answer:
An excellent experiment is to heat sodium thiosulfate in a water bath. The solid crystals will dissolve into the water in the hydrated crystals forming a supersaturated solution. ... Placing a small crystal in the supersaturated solution will cause the liquid to turn solid.
Metals are on the left side of the table and nonmetals are on the left with metalloids between them. And the noble gases are all in group 18 of the periodic table.
