Answer:
21.3 g. Option B
Explanation:
The reaction is:
4HF(g) + SiO₂(s) → SiF₄(g) + 2H₂O(g)
We analysed it and it is correctly balanced.
4 moles of hydrogen fluoride react to 1 mol of silicon dioxide in order to produce 1 mol of silicon fluoride and 2 moles of water vapor.
We determine molar mass of each reactant:
HF → 1.01 g/mol + 19 g/mol = 20.01 g/mol
SiO₂ → 16 g/mol . 2 + 28.09 g/mol = 60.09 g/mol
We convert mass to moles: 16 g . 1 mol /60.09g = 0.266 moles of glass
Ratio is 1:4. 1 mol of glass react to 4 moles of HF
Our 0.266 moles may react to (0.266 . 4) / 1 = 1.07 moles of gas
We convert moles to mass: 1.07 mol . 20.01 g/mol = 21.3 g
Answer:
freezing point
Explanation:
melting point is what temperature a solid turns into a liquid,
freezing point is what temperature a liquid turns into a solid
Answer:
The van't hoff factor of 0.500m K₂SO₄ will be highest.
Explanation:
Van't Hoff factor was introduced for better understanding of colligative property of a solution.
By definition it is the ratio of actual number of particles or ions or associated molecules formed when a solute is dissolved to the number of particles expected from the mass dissolved.
a) For NaCl the van't Hoff factor is 2
b) For K₂SO₄ the van't Hoff factor is 3 [it will dissociate to give three ions one sulfate ion and two potassium ions]
Out of 0.500m and 0.050m K₂SO₄, the van't hoff factor of 0.500m K₂SO₄ will be more.
c) The van't Hoff factor for glucose is one as it is a non electrolyte and will not dissociate.
Molecular mass of C₂H₄ is,
M = 2×12 + 4×1 g/mol
M = 28 g/mol
Moles of C₂H₄ in 5.6 g of C₂H₄ :
n = 5.6/28 mol
n = 0.2 mol
Now, 1 mol of C₂H₄ contains 2 moles of carbon.
So, number of moles of carbon are :
n = 0.4 mol
We know, 1 mol of any atom contains 6.022 × 10²³ atoms.
So, number of carbon atoms are :
Hence, this is the required solution.
Answer:
Antibacterial specifically refers to an inhibition of growth of bacteria, whereas antibiotics refer to a general inhibition of growth of microorganisms, which could include bacteria and viruses.