When a substance is changing state, its temperature remains constant. This is because energy is used to increase/decrease kinetic energy of the molecules of the substance, increasing/decreasing the inter-molecular distance and overcoming the energy bonds present between the molecules. Therefore, no energy is used to raise the temperature of the substance and therefore it remains constant
<span><span>Convert the percentages into decimals (you can do that by dividing the percent by 100), then multiply that by its
corresponding mass to find its relative amount/ contribution to the
atomic mass of chromium. After doing so, add all of the obtained values
together to get the average mass.
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83.79% = .08379
9.50% = .095
4.35% = .0435
2.36% = .0236
Average mass of chromium = 0.8379(51.94) + 0.095( 52.94) + 0.0435(49.95) + 0.0236(53.94)
Answer: 52amu
P.S. never forget units
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It is a.combination that is the correct answer i think
Answer: 11, Na, 23, 100, −9.529 ... phosphorus, 15, P, 31, 100, −24.441 ... manganese, 25, Mn, 55, 100, −57.706.
Explanation: Make me Brainelist
Answer:
0.259 kJ/mol ≅ 0.26 kJ/mol.
Explanation:
- To solve this problem, we can use the relation:
<em>Q = m.c.ΔT,</em>
where, Q is the amount of heat absorbed by ice (Q = ??? J).
m is the mass of the ice (m = 100.0 g).
c is the specific heat of water (c of ice = 4.186 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 21.56°C - 25.0°C = -3.44°C).
<em>∵ Q = m.c.ΔT</em>
∴ Q = (100.0 g)(4.186 J/g.°C)(-3.44°C) = -1440 J = -1.44 kJ.
<em>∵ ΔH = Q/n</em>
n = mass/molar mass = (100.0 g)/(18.0 g/mol) = 5.556 mol.
∴ ΔH = (-1.44 kJ)/(5.556 mol) = 0.259 kJ/mol ≅ 0.26 kJ/mol.