Answer:
98.6 g/mol.
Explanation:
Equation of the reaction
HX + NaOH--> NaX + H2O
Number of moles = molar concentration × volume
= 0.095 × 0.03
= 0.00285 moles
By stoichiometry, 1 mole of HX reacted with 1 mole of NaOH. Therefore, number of moles of HX = 0.00285 moles.
Molar mass = mass ÷ number of moles
= 0.281 ÷ 0.00285
= 98.6 g/mol.
3-B
4-C
5-A
6-A
7-C
8-B
9-A
10-B
Answer:

Explanation:
From the question we are told that:
1st Energy 
2nd Energy 
3rd Energy 
Generally the equation for Energy E for electron in one dimensional box at ground state
is mathematically given by


Therefore Length a is mathematically given as



Answer:
A. Has only one kind of atom
Explanation:
All forms of matter are composed of elements.
An element is a substance which cannot be broken down into simpler units or converted into other substances by ordinary chemical reactions. Each element is composed of only one kind of atoms which are unique to each element. There are three fundamental sub-particles present in atoms of elements; these are: protons, electrons and neutrons. An atom of an element differs from an atom of another element by its atomic number. The atomic number of an element is the number of protons present in the nucleus of the atom of that element. For example, hydrogen atoms has an atomic number of 1, while sodium atoms has an atomic umber of 11.
Atoms of the same element or different elements may combine together to form the molecules of a substance. For example, a molecule of hydrogen gas is made up of two atoms of hydrogen whereas a molecule of water is composed of two atoms of hydrogen and an atom of oxygen.
Elements can exist in any of the three physical states: solids, liquids or gases. For example, hydrogen exists as gas, mercury as a liquid, while gold exists as a solid.
Answer:
Dilute
Explanation:
A concentrated solutions is a one which has relatively large amount of dissolved solute in the solution whereas a dilute solution is a one which has relatively lower concentration of dissolved solute.
In the given solution there is only 3.3% of solute. So, we can say that the given solution is a dilute solution. However, these terms are relative.