Answer:
mass of HCl = 3.65 g
Explanation:
Data Given:
Moles of hydrochloric acid HCl = 0.1 mole
Mass in grams of hydrochloric acid HCl = ?
Solution:
Mole Formula
no. of moles = Mass in grams / molar mass
To find Mass in grams rearrange the above Formula
Mass in grams = no. of moles x molar mass . . . . . . . (1)
Molar mass of HCl = 1 + 35.5 = 36.5 g/mol
Put values in equation 1
Mass in grams = 0.1 mole x 36.5 g/mol
Mass in grams = 3.65 g
mass of HCl = 3.65 g
Each of the following are descriptions of physical properties except C. Flammability
Answer is: coefficient is one.
Chemical reaction: SiO₂ + 4HF → SiF₄ + 2H₂O.
Reaction is balanced when there are equal numbers of elements in both side of the chemical reaction.
HF - hydrofluoric acid, <span>highly corrosive, dissolves many materials.</span>
SiF₄ - silicon tetrafluoride.
Answer: 250 kJ
Explanation: According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to Hess’s law, the chemical equation can be treated as algebraic expressions and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
(1)
(2)
Net chemical equation:
(3)
Adding 1 and 2 we get,
(4)
Now dividing equation (4) by 4, we get
(4)
It should be 24 electrons
