Does standard enthalpy use net ionic equations?a. Trueb. False
1 answer:
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Answer:
3.74 x 10²² particles
Explanation:
Given parameters:
Mass of compound = 1.43g
Molar mass of compound = 23g
Unknown:
Number of particles of sodium = ?
Solution:
To find the number of particles of Na in the compound, we need to obtain the mass of sodium from the total mass given;
Mass of sodium =
=
= 1.43g
Now find the number of moles of this amount of Na in the sample;
Number of moles = =
= 0.062mole
Now;
1 mole of substance = 6.02 x 10²³ particles
0.062 mole of substance = 0.062 x 6.02 x 10²³ particles
= 3.74 x 10²² particles
Answer: The correct answer is option B.
Explanation: There are 7 elements in group VIII-A. They are Helium (He), Neon(Ne), Argon(Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) and Ununoctium (Uuo). They are considered as a part of group 18.
Metals are shown in purple color in the periodic table. Metalloids as blue color and Non-metals are shown in green color.
Group VIII-A elements have fully filled orbitals and hence are most stable amongst all the elements in the periodic table. They are considered as least reactive elements and as they are categorized as non-metals. So, they are the least reactive non-metals.
Therefore, the correct option is B.
