Bohr’s theory was inadequate because it did not explain the energies absorbed and released by atoms with more than one electron. It worked well for hydrogen atoms but did not work when applied to more complex atoms.
Empirical formula is the simplest formula showing the simplest ratio of atoms in a compound. Calculated as shown;
we start by calculating the number of moles of each atom;
moles of nickel = 9.11 g ÷ 58.7 g = 0.155 moles
moles of fluorine = 5.89 g ÷ 19 g = 0.31 moles
Then we get the ratio of the moles of nickel to that of flourine
That is 0.155 : 0.31 (dividing by the smallest)
0.155/0.155 : 0.31/0.155
we get 1:2 ( the simplest ratio)
Therefore the empirical formula is nif2
Answer:
The heat of combustion is -25 kJ/g = -2700 kJ/mol.
Explanation:
According to the Law of conservation of energy, the sum of the heat released by the combustion reaction and the heat absorbed by the bomb calorimeter is equal to zero.
Qcomb + Qcal = 0
Qcomb = - Qcal
The heat absorbed by the calorimeter can be calculated with the following expression.
Qcal = C × ΔT
where,
C is the heat capacity of the calorimeter
ΔT is the change in temperature
Then,
Qcomb = - Qcal
Qcomb = - C × ΔT
Qcomb = - 1.56 kJ/°C × 3.2°C = -5.0 kJ
Since this is the heat released when 0.1964 g o quinone burns, the energy of combustion per gram is:
The molar mass of quinone (C₆H₄O₂) is 108 g/mol. Then, the energy of combustion per mole is:
The list of options to answer this question is:
A.kinectic energy is transformed into thermal energy.
B.electrical energy is transformed into potential energy.
C.potential energy is transformed into kinectic energy.
D.mechanical energy is transformed into chemical energy.
The answer is the option A. A.kinectic energy is transformed into thermal energy.
As you know energy cannot be lost but transformed.
When friction force acts over the tyres it increases the speed of the particles in the tyres which is thermal energy, this thermal energy increase comes from kinetic energy loss.
Answer: Read Explanation
Explanation: Index fossils are useful because they tell the relative ages of the rock layers in which they occur. Geologists use particular types of organisms, such as trilobites, as index fossils.
