Solution of 0.25 M is prepared in two steps,
1) Calculate Amount of Solute:
Molar Mass of Solute: 342.3 g/mol
As we know,
Molarity = Moles / 1 dm³
or,
Moles = Molarity × 1 dm³
Putting Values,
Moles = 0.25 mol.dm⁻³ × 1 dm³
Moles = 0.25 moles
Now, find out mass of sucrose,
As,
Moles = Mass / M.mass
or,
Mass = Moles × M.mass
Putting Values,
Mass = 0.25 mol × 342.3 g.mol⁻¹
Mass = 85.57 g
2) Prepare Solution:
Take Volumetric flask and add 85.57 g of sucrose in it. Then add distilled water up to the mark of 1 dm³. Shake well! The solution prepared is 0.25 M in 1 Liter.
Answer: the atomic number 7 is
Nitrogen
Explanation:
The main points of Dalton's atomic theory are: Everything is composed of atoms, which are the indivisible building blocks of matter and cannot be destroyed. All atoms of an element are identical. The atoms of different elements vary in size and mass.
P = pressure, V = volume, T = absolute temperature k = constant.
Answer:

Explanation:
= Initial pressure = 931 torr = 
= Final pressure = 113 kPa
= Initial volume = 350 mL
= Final volume
From the Boyle's law we have

The volume the gas would occupy is
.