Answer:
<em>Valency is the combining power of an element. Elements in the same group of the periodic table have the same valency. The valency of an element is related to how many electrons are in the outer shell. The noble gases have the valency 0 as they do not usually combine with other elements.</em>
Explanation:
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Answer:
818.2 g.
Explanation:
- Molarity is the no. of moles of solute per 1.0 L of the solution.
<em>M = (no. of moles of NaCl)/(Volume of the solution (L))</em>
<em></em>
M = 2.0 M.
no. of moles of NaCl = ??? mol,
Volume of the solution = 7.0 L.
∴ (2.0 M) = (no. of moles of NaCl)/(7.0 L)
∴ (no. of moles of NaCl) = (2.0 M)*(7.0 L) = 14.0 mol.
- To find the mass of NaCl, we can use the relation:
<em>no. of moles of NaCl = mass/molar mass</em>
<em></em>
<em>∴ mass of NaCl = (no. of moles of NaCl)*(molar mass) =</em> (14.0 mol)*(58.44 g/mol) = <em>818.2 g.</em>
Endothermic reactions. These are reactionsthat take in energy from the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to get colder
Answer:
Oil has the smaller heat capacity. The effectiveness of the heat exchanger is 0.80.
Explanation:
Part 1:
In order to know which fluid has the smaller heat capacity we need to consider the heat equation below:
Q = CΔT, where Q is the heat exchanged, C is the heat capacity and ΔT is the variation in temperature.
As the heat exchange is the same for both fluids, the smaller the temperature variation, the smaller the heat capacity.
Water: ΔT = 120 °F
Oil: ΔT = 80 °F
Therefore, oil is the fluid with the smallest heat capacity.
Part 2:
The effectiveness of a counter-flow heat exchanger is given by the equation bellow:
Th1: initial temperature of the hot fluid
Th2: final temperature of the hot
Tc1: initial temperature of the cold fluid
