<u>Answer:</u> The amount of calcium hydroxide needed to react is 2.04 moles
<u>Explanation:</u>
We are given:
Moles of phosphoric acid = 1.36 moles
For the given chemical equation:
By Stoichiometry of the reaction:
2 moles of phosphoric acid reacts with 3 moles of calcium hydroxide
So, 1.36 moles of phosphoric acid will react with = 
of calcium hydroxide
Hence, the amount of calcium hydroxide needed to react is 2.04 moles
94.20 g/3.16722 mL = 29.74 g/mL
The ratio of mass to volume is equal to the substance's density. Thus, 29.74 g/mL is the density of whatever substance it may be. Density does not change for incompressible matter like solid and some liquids. Although, it may be temperature dependent.
Answer:
The true statement is option A.
Explanation:
Using ideal gas equation:
PV = nRT
where,
P = Pressure of gas = 1 atm
V = Volume of gas = ?
n = number of moles of gas = 1 mol
R = Gas constant = 0.0821 L.atm/mol.K
T = Temperature of gas = 273.15 K
V = 22.42 L
This means that 1 mole of an ideal gas at STP occupies 22.42 liters of volume.
So, 1 mole of helium gas and 1 mole of oxygen gas will have same value of volume in their respective balloons at STP.
Q1)
the number of moles can be calculated as follows
number of moles = mass present / molar mass
number of moles is the amount of substance.
4.8 g of Ca was added therefore mass present of Ca is 4.8 g
molar mass of Ca is 40 g/mol
molar mass is the mass of 1 mol of Ca
therefore if we substitute these values in the equation
number of moles of Ca = 4.8 g / 40 g/mol = 0.12 mol
0.12 mol of Ca is present
q2)
next we are asked to calculate the number of moles of water present
again we can use the same equation to find the number of moles of water
number of moles = mass present / molar mass
3.6 g of water is present
sum of the products of the molar masses of the individual elements by the number of atoms
H - 1 g/mol and O - 16 g/mol
molar mass of water = (1 g/mol x 2 ) + 16 g/mol = 18 g/mol
molar mass of H₂O is 18 g/mol
therefore number of moles of water = 3.6 g / 18 g/mol = 0.2 mol
0.2 mol of water is present
The only compound that contains covalent bonds would be A. BCl4-.
