There are 9.8 moles of sodium (Na) in a sample of 5.87 x 10²⁴ atoms of sodium.
<h3>HOW TO CALCULATE NUMBER OF MOLES?</h3>
The number of moles of a substance can be calculated by dividing the number of molecules in the substance by Avogadro's number. That is;
no. of moles = no. of atoms ÷ 6.02 × 10²³
According to this question, there are 5.87 x 10²⁴ atoms of sodium. The number of moles is as follows:
no. of moles = 5.87 x 10²⁴ atoms ÷ 6.02 × 10²³
no. of moles = 0.98 × 10¹
no. of moles = 9.8moles
Therefore, there are 9.8 moles of sodium (Na) in a sample of 5.87 x 10²⁴ atoms of sodium.
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The correct option is this: WHEN THE ENTHALPY CHANGE OF THE REACTION IS POSITIVE, THE REACTION IS ENDOTHERMIC.
All chemical reactions are divided into two classes, these are exothermic and endothermic reaction. An exothermic reaction is a type of reaction in which energy is lost to the environment, thus the enthalpy change of the reaction is negative. An endothermic reaction is a type of reaction in which energy is absorbed from the environment, thus the enthaply change of the reaction is positive.
Answer:
100 kPa
Explanation:
This can be solved with one of the gases law. This law establishes that the pressure of the gas is directly proportional to its temperature: If we increase the temperature, the pressure will increase.
In this case, we decrease the temperature, so its pressure will be lower.
P₁ / T₁ = P₂ / T₂
We convert T° to Absolutes Values
27°C + 273 = 300 K
-173°C + 273 = 100 K
300 kPa / 300 K = P₂ / 100 K
(300 kPa / 300 K) . 100K = P₂
P₂ = 100 kPa
This is the Charles Gay Lussac's law.
Answer : The correct option is, (B) bimolecular
Explanation :
Molecularity : It is defined as the total number of reactant molecules taking part in the balanced equation of a reaction. It is a theoretical concept.
The given balanced chemical reaction is,
The number of reactants molecules taking part in the balanced equation of a reaction are, and .
In this reaction, 1 molecules reacts with the 1 molecule.
Total number of reactant molecule = 1 + 1 = 2
The molecularity of the reaction is 2 that means, the elementary reaction is bimolecular.
Hence, the correct option is, (B) bimolecular
Oxygen = 16
Iron = 55.8
16 x 27.6% = 4.4 /4 = 1.1
55.8 x 72.4% = 40.4 /4 = 10.1
1 oxygen and 10 iron, so Fe10 O