Δ H reaction = q / n where q: amount of heat released and n is number of moles of substance.
q = m . C . ΔT where:
m = mass of substance (g)
C = Specific heat capacity (4.18)
ΔT = change in temperature = 24.25 - 23.16 = 1.09
q = 1000 x 4.18 x 1.09 = 4556 J = 4.556 kJ
number of moles (n) = Molarity (M) x Volume (L)
= 0.185 M x 0.07 L = 0.01295 mole
Δ H = q / n = - (4.556 kJ / 0.01295 mole) = -351.8 kJ / mol
Note: it is exothermic reaction (-ve sign) i.e. temperature is raised
The number of atoms of gold in the pure ring are 7.18 × 10²² atoms.
<h3>HOW TO CALCULATE NUMBER OF ATOMS?</h3>
The number of atoms in a substance can be calculated by multiplying the number of moles of the substance by Avogadro's number.
The number of moles in the gold (Au) can be calculated by dividing the mass of gold by its molar mass (196.97g/mol).
no. of moles = 23.5g ÷ 196.97g/mol
no. of moles = 0.119mol
Number of atoms in Au = 0.119 × 6.02 × 10²³
no. of atoms = 7.18 × 10²² atoms.
Therefore, the number of atoms of gold in the pure ring are 7.18 × 10²² atoms.
Learn more about number of atoms at: brainly.com/question/15959704
Answer:
B. A body at rest will stay at rest until it is acted upon by another object
Explanation:
Newton's first law states that if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
I remember I had the same question I think it was Sedementation
