How much energy is needed to heat enough water to make a cup of tea (250 ml), if the water is initially at 20.0°C and you want to increase the temperature to 85.0°C? (1.00 mL of water has a mass of 1.00 g.)As the tea in the previous question steeps, it cools from 85.0°C to 75.0°C. How much energy is lost by the tea as it steeps?
Answers
Answer:
Heat Energy needed (Q) = 68250 J
Energy lost (Q') = 10500 J
Explanation:
Applying,
Q = cm(t₂-t₁)............. Equation 1
Where Q = heat energy needed, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature.
From the question,
Given: m = 250 g = 0.25 kg, t₁ = 20.0°C, t₂ = 85.0°C
Constant: c = 4200 J/kg°C
Substitute these values into equation 1
Q = 0.25(4200)(85-20)
Q = 68250 J.
Similarly, heat lost
Q' = cm(t₁-t₂)................. Equation 2
Where Q = heat lost
Given: t₁ = 85°C, t₂ = 75°C
Substitute into equation 2
Q' = 4200(0.25)(85-75)
Q' = 10500 J
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Answer: It is a Heterogeneous mixture.
Final answer:
The beaker contains a mixture of three solids, namely flour, sugar, and baking soda. These components retain their properties in the mixture and are not chemically combined.
Explanation:
The contents of the beaker can be described as a mixture. A mixture is a combination of two or more substances that are not chemically combined. In this case, the beaker contains flour, sugar, and baking soda. These are solid substances that maintain their own properties in the mixture. They're simply combined in the same space (the beaker), but they are not interacting on a molecular level to form a new substance.
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Answers
i take chemistry rn lol
G The electrons are outside the nucleus and have no charge.
H The electrons are inside the nucleus and have a negative charge.
The electrons are outside the nucleus and have a negative charge.
which is correct
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Answer:
D. The electrons are outside the nucleus and have a negative charge.
Explanation:
Electrons are located outside the nucleus while protons and neutrons are located inside the nucleus.
Electrons are negatively charged and attracted to nucleus as the nucleus carry protons that are positively charged and neutrons have no charge.
Electrons are arranged in different energy levels based on the attraction between the positively charged nucleus and negatively charged electron.
Hence, the correct answer is "D. The electrons are outside the nucleus and have a negative charge."
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Answer : The value of the rate constant for the forward reaction at 700 K is,
Explanation :
The given chemical equilibrium reaction is:
The expression for equilibrium constant is:
The expression for rate of forward and backward reaction is:
and,
As we know that at equilibrium rate of forward reaction is equal to rate of backward reaction.
Given:
Now put all the given values in the above expression we get:
Therefore, the value of the rate constant for the forward reaction at 700 K is,
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Each line represents a single bond (two electrons), and the lone pairs of electrons are shown as dots. Carbon forms single bonds with three hydrogen atoms and one bromine atom, resulting in a stable Lewis structure that satisfies the octet rule for each element and minimizes formal charges.
To draw the Lewis electron-dot diagram for bromomethane (CH3Br), follow these steps:
Determine the total number of valence electrons for each element in the molecule:
Carbon (C) has 4 valence electrons.
Hydrogen (H) has 1 valence electron.
Bromine (Br) has 7 valence electrons.
Calculate the total number of valence electrons by adding the contributions from each element:
Carbon: 4 electrons x 1 atom = 4 electrons.
Hydrogen: 1 electron x 3 atoms = 3 electrons.
Bromine: 7 electrons x 1 atom = 7 electrons.
Total = 4 + 3 + 7 = 14 electrons.
Determine the central atom. In CH3Br, carbon is the central atom.
Connect the central carbon atom to the surrounding hydrogen and bromine atoms using single bonds (each bond consists of two electrons).
Distribute the remaining valence electrons as lone pairs on the outer atoms to satisfy the octet rule. Hydrogen can only accommodate two electrons (a duet), and bromine can expand its octet.
Calculate the formal charges to ensure that the Lewis structure represents the most stable arrangement of electrons. In CH3Br, the formal charges should ideally be as close to zero as possible.
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