Answer:
Mass = 55.52 g
Explanation:
Given data:
Number of atoms of Li = 4.81×10²⁴ atom
Number of grams = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For Li:
4.81×10²⁴ atom × 1 mol / 6.022 × 10²³ atom
8 moles
Mass in gram:
Mass = number of moles × molar mass
Mass = 8 mol × 6.94 g/mol
Mass = 55.52 g
Answer is: the osmotic pressure of aqueous solution of aspirin is 0.0407 atm.
m(C₉H₈O₄) = 75 mg ÷ 1000 mg/g = 0.075 g.
n(C₉H₈O₄) = 0.075 g ÷ 180.16 g/mol.
n(C₉H₈O₄) = 0.000416 mol.
c(C₉H₈O₄) = 0.000416 mol ÷ 0.250 L.
c(C₉H₈O₄) = 0.00167 M; concentration of solution.
T(C₉H₈O₄) = 25°C = 298.15 K; temperature in Kelvins.
R = 0.08206 L•atm/mol•K; universal gas constant.
π = c(C₉H₈O₄) • T(C₉H₈O₄) • R.
π = 0.00167 mol/L • 298.15 K • 0.08206 L•atm/mol•K.
π = 0.0407 atm.
The compound Fe(NO2)2 is Iron (II) Nitrite.
Hope I could help :)
Answer:
1400KJ/mol⁻¹
Explanation:
Amount of heat required can be found by:
Q = m × c × ΔT
<em>Where m is the mass, c is the specific heat capacity (4.2KJ for water) and ΔT is the change in temperature.</em>
Q = 24 × 4.2 × (23 - 9)
= 24 × 4.2 × 14
= 1411.2KJ/mol⁻¹
= <u>1400KJ/mol⁻¹</u> (to 2 significant figures)
