Answer:
14.93 g
Explanation:
First we <u>convert 1.2 x 10²³ atoms of arsenic (As) into moles</u>, using <em>Avogadro's number</em>:
- 1.2 x 10²³ atoms ÷ 6.023x10²³ atoms/mol = 0.199 mol As
Then we can<u> calculate the mass of 0.199 moles of arsenic</u>, using its<em> molar mass</em>:
- 0.199 mol * 74.92 g/mol = 14.93 g
Thus, 1.2x10²³ atoms of arsenic weigh 14.93 grams.
First, consider the steps to heat the sample from 209 K to 367K.
1) Heating in liquid state from 209 K to 239.82 K
2) Vaporaizing at 239.82 K
3) Heating in gaseous state from 239.82 K to 367 K.
Second, calculate the amount of heat required for each step.
1) Liquid heating
Ammonia = NH3 => molar mass = 14.0 g/mol + 3*1g/mol = 17g/mol
=> number of moles = 12.62 g / 17 g/mol = 0.742 mol
Heat1 = #moles * heat capacity * ΔT
Heat1 = 0.742 mol * 80.8 J/mol*K * (239.82K - 209K) = 1,847.77 J
2) Vaporization
Heat2 = # moles * H vap
Heat2 = 0.742 mol * 23.33 kJ/mol = 17.31 kJ = 17310 J
3) Vapor heating
Heat3 = #moles * heat capacity * ΔT
Heat3 = 0.742 mol * 35.06 J / (mol*K) * (367K - 239.82K) = 3,308.53 J
Third, add up the heats for every steps:
Total heat = 1,847.77 J + 17,310 J + 3,308.53 J = 22,466.3 J
Fourth, divide the total heat by the heat rate:
Time = 22,466.3 J / (6000.0 J/min) = 3.7 min
Answer: 3.7 min
Answer:
Sue was not right as wood is not a heat conductor and will not allow heat to pass through the spoon thus keeping the hand safe. In a meatal spoon, heat can pass through and burn the hand as meatal is a good conductor of heat.
