Answer:

Explanation:
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In this case, according to the Avogadro's number, it is possible to compute the atoms of Kr in 2.00 moles as shown below:

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Answer:</h3>
1031.4 Calories.
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Explanation:</h3>
We are given;
Mass of the copper metal = 50.0 g
Initial temperature = 21.0 °C
Final temperature, = 75°C
Change in temperature = 54°C
Specific heat capacity of copper = 0.382 Cal/g°C
We are required to calculate the amount of heat in calories required to raise the temperature of the copper metal;
Quantity of heat is given by the formula,
Q = Mass × specific heat capacity × change in temperature
= 50.0 g × 0.382 Cal/g°C × 54 °C
= 1031.4 Calories
Thus, the amount of heat energy required is 1031.4 Calories.
Answer:
2OH^-(aq) + Cu^2+(aq) -----> Cu(OH)2(s)
Explanation:
The net ionic equation usually shows the main ionic reaction that goes in the system. The other ions that do not participate in this net ionic equation are called spectator ions. Spectator ions do not participate in the main reaction occurring in the system.
The net ionic equation quite often result in the formation of a solid precipitate in the system such as Cu(OH)2.
The net ionic equation for this reaction is;
2OH^-(aq) + Cu^2+(aq) -----> Cu(OH)2(s)
Write an balance the equation
Na2O + H2O -> 2 NaOH
Calculate the molecular mass of Na2O and NaOH from the atomic mass from the periodic table.
Na = 23
O=16
H=1
Na2O = 23 * 2 + 16 = 62
NaOH = 23+16+1= 40
For the stoichiometry of the reaction one mole of Na2O = 62g produce two mol of NaOH = 2* 40= 80 g
120 g Na2O x 80g NaOH / 62g Na2O=
154.8 g NaOH