Answer : The total change in enthalpy of this reaction is 25 kJ.
Explanation :
Enthalpy of reaction : It is defined as the changes in heat energy takes place when reactants go to products. It is denotes as .
ΔH = Energy of product - Energy of reactant
ΔH is positive when heat is absorbed and the reaction is endothermic.
ΔH is negative when heat is released and the reaction is exothermic.
In the given potential energy diagram, the energy of product at higher level and energy of reactant at lower level. The ΔH for this reaction will be positive.
Given:
Energy of product = 55 kJ
Energy of reactant = 30 kJ
ΔH = Energy of product - Energy of reactant
ΔH = 55 kJ - 30 kJ
ΔH = 25 kJ
Thus, the total change in enthalpy of this reaction is 25 kJ.
The balanced chemical reaction is:
HNO3 + NaOH = NaNO3 + H2O
We are given the amount and concentration of the reactants. The values given will be the starting point.
0.20 mol /L HNO3 (.015 L) (1 mol NaOH / 1 mol HNO3) = 0.003 mol NaOH
0.003 mol NaOH / 0.10 mol/ L NaOH = 0.03 L NaOH or 30 mL NaOH
Answer:
Explanation:
To convert from mole to atoms, we must use Avogadro's Number: 6.022*10²³. This number tells us the particles (atoms, ions, molecules, etc.) in 1 mole of a substance. In this case, the particles are atoms of argon.
Let's create a ratio.
Multiply by the given number of atoms.
Flip the fraction so the atoms of argon will cancel.
The original measurement of atoms has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place. The 8 in the thousandth place tells us to round the 9 to a 0, which also rounds the 9 in the tenths place to a 0, then the 4 to a 5.
There are 5.00 moles of argon.
Krypton is in group 18, and so it has 8 valence electrons. B is the answer
Answer: The correct answer is Chlorine (Cl).
Explanation: Electronegativity is the property of an element to attract the shared pair of electron towards itself. In a periodic table, the electronegativity increases as we move from left to right and it decreases as we move from top to bottom.
The location of the given elements are:
Barium (Ba): It belongs to Group 2 and Period 6 of the periodic table.
Chlorine (Cl): It belongs to Group 17 and Period 3 of the periodic table.
Iodine (I): It belongs to Group 17 and Period 5 of the periodic table.
Strontium (Sr): It belongs to Group 2 and Period 5 of the periodic table.
From the above information, Chlorine belongs to the lowest period and greatest group number. Hence, it has the highest electronegativity and will attract the shared pair of electron towards itself strongly.
Therefore, the correct answer is Chlorine (Cl).
