Answer:
If 700 g of water at 90 °C loses 27 kJ of heat, its final temperature is 106.125 °C
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
In this way, between heat and temperature there is a direct proportional relationship (Two magnitudes are directly proportional when there is a constant so that when one of the magnitudes increases, the other also increases; and the same happens when either of the two decreases .). The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat and the mass of the body. So, the equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature, ΔT= Tfinal - Tinitial
In this case:
- Q= 27 kJ= 27,000 J (being 1 kJ=1,000 J)
- m=700 g
- ΔT= Tfinal - Tinitial= Tfinal - 90 °C
Replacing:
Solving:
16.125 °C= Tfinal - 90 °C
Tfinal= 16.125 °C + 90 °C
Tfinal= 106.125 °C
<u><em>If 700 g of water at 90 °C loses 27 kJ of heat, its final temperature is 106.125 °C</em></u>
Answer:
See explanation
Explanation:
If the energy of the ground state E1 is known, then we need to measure the difference in energy between the energy levels E5 .and E1. We can obtain this by measuring the frequency or wavelength of a photon that is emitted when an electron moves from energy level E5 to E1.
From Bohr's model;
ΔE = E5 - E1
Hence;
E5 = ΔE + E1
Answer:
See explanation
Explanation:
Given that the formula of the compound is Fe2O3, if a coefficient of 2 is placed in front of the formula, that is, if we write 2Fe2O3 . Then;
The number of Fe atoms becomes 2 *2 = 4
The number of oxygen atoms becomes 2*3 = 6
That is why the total number of iron atoms were written down as 4.
It is 2.1 x 10^3 because your base number needs to be in between 1 and 10, and the number you are converting is non-decimal, so the exponent is positive. It is 10^3 because you are moving the decimal 3 places to the right
First, it is best to know the chemical formula of pyridine which is C5H5N. To determine the number of carbon atoms present in pyridine, multiply 7.05 mol C5H5N with 5 mol C/ 1 mol C5H5N which then results to 35.35 mol of carbon. Then, multiply the answer to Avogadro's number which is 6.022x10^23 atoms. It is then calculated that the number of carbon atoms in 7.05 moles of pyridine is 2.12x10^25 atoms.
