The residential end-use sector has the largest seasonal variance, with significant spikes in demand every summer and winter. Virtually all homes that have air conditioning use electricity as the main source of cooling in the summer, while winter heating needs are met by a variety of fuels. Some homes use electric resistance heating and electric heat pumps, but even homes with other heating fuels such as natural gas or fuel oil still use some electricity to power furnace fans, boiler circulation pumps, and compressors.
The commercial sector experiences less variance in electricity use, although it shows a noticeable increase in the summer and a slight increase in the winter. Compared to the residential sector, a smaller portion of commercial sector energy consumption is devoted to heating, cooling, and ventilation. However, other energy fuels beyond electricity can be used in the commercial sector to meet both heating and cooling needs. For example, some commercial buildings use natural gas-fired chillers for cooling.
The industrial sector's demand for electricity is relatively flat (with just a slight increase in the summer) because a much smaller portion of its energy consumption (electric and otherwise) is used for heating and cooling. Economic variables generally play a larger role in industrial energy use than weather-related factors. However, seasonal changes can affect industrial activity. For example, in the refining industry, different seasonal slates of petroleum products as well as different seasonal processes may affect electricity needs.
Answer:
The time taken for the cross to become invisible decreases.
Explanation:
We know that one of the factors affecting the rate of reaction is the concentration of reactants. From the collision theory, we know that the higher the concentration of reactants, the greater the possibility of effective collision between reactants leading ultimately to an increase in the rate of reaction. Increase in the rate of reaction implies that the reaction takes a shorter time to reach completion.
In the case of the reaction shown in the question, the point when the reaction is completed is observed by the time take for the cross mark to become invisible. If we look at the given data closely, we will notice that the volume of acid was held constant, the volume of thiosulphate was increased gradually while the volume of water was decreased accordingly. This implies that the concentration of the reactants was increased. Decreasing the volume of water increases reactant concentration.
As explained above, increase in reactant concentration increases the rate of reaction. Hence, the rate of reaction of the acid and thiosulphate increases as reactant concentration increases and the cross mark becomes invisible faster. This implies that in the last column for time taken for the cross to become invisible, the values of time decreases steadily as concentration of reactants increases.
The geosphere is about 99.94% of Earth's mass, so C is the answer.
Answer:
A) Forward rate = 1.1934 × 10^(-4) M/min
B) I disagree with the claim
Explanation:
A) We are told that [HF] reaches a constant value of 0.0174 M at equilibrium.
The reversible reaction given to us is;
BF4-(aq) +H20(l) → BF3OH-(aq) + HF(aq)
From this, we can see that the stoichiometric ratio is 1:1:1:1
Thus, concentration of [BF4-] is now;
[BF4-] = 0.150 - 0.0174
[BF4-] = 0.1326 M
From the rate law, we are told the forward rate is kf [BF4-].
We are given Kf = 9.00 × 10^(-4) /min
Thus;
Forward rate = 9.00 × 10^(-4) /min × (0.1326M)
Forward rate = 1.1934 × 10^(-4) M/min
(B) The student claims that the initial rate of the reverse reaction is equal to zero can't be true because at equilibrium, rates for the forward and reverse reactions are usually equal.
Thus, I disagree with the claim.
Summer Solstice is what happens when part of the Earth's surface is tilted towards the sun..
