Answer:
C) 
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
The expression of the pH of the calculation of weak acid is:-
Where, C is the concentration = 0.5 M
Given, pH = 2.94
Moles = 0.100 moles
Volume = 1.00 L
So, 
C = 0.100 M
Explanation:
The mass per unit volume of a substance is called density .
Answer:
D) atomic radii increase from top to bottom of a group
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Other options are incorrect because,
A) atomic radii increase from left to right across the period
Correct = atomic radii decreases from left to right across the period
B) ionization energy increases from top to bottom within a family
Correct = ionization energy decreases from top to bottom within a family
C) electronegativity decreases from left to right across a period
Correct = electronegativity increases from left to right across a period
Equation is:
Ca(NO3)2 + Na3PO4 —> NaNO3 + Ca3(PO4)2
Balance it out
3Ca(NO3)2 + 2Na3PO4 —> 6NaNO3 + Ca3(PO4)2
You have 96.1g of Calcium Nitrate
Moles = Mass/Molar Mass
Molar mass of Calcium Nitrate is 164.088 g/mol
96.1g / 164.088 g/mol =0.586 moles
Mole ratio is 3:1
Therefore 0.586/3 moles of calcium phosphate
Moles x molar mass = mass
0.586/3 x 310.18 g/mol = 60.6~g roughly as theoretical yield
