89.1% Au
The molar mass of Au2O3 is 2(196.97) + 3(16.00) = 441.94 g/mol
The mass percent of Au is therefore 2(196.97) / 441.94, which is 393.94/441.94 = 0.891 —> 89.1%
The answer is the plague, or the black death
Answer:
2621.75 j heat is required to increase the temperature 25.5°C to 46°C.
Explanation:
Given data:
Mass of sample = 142.1 g
Initial temperature = 25.5°C
Final temperature = 46°C
Specific heat capacity of Al = 0.90 J/g.°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 46°C - 25.5°C
ΔT = 20.5°C
Q = 142.1 × 0.90 J/g.°C × 20.5°C
Q = 2621.75 j
Thus, 2621.75 j heat is required to increase the temperature 25.5°C to 46°C.
2O3→3O2
The number of moles of O2 that are produced when 0.50 moles of O3(g) reacted is 0.75 moles
calculation and explanation
2 moles of O3(ozone) react to give 3 moles of O2 (oxygen gas,therefore the reacting ratio between O3 :O2 is 2:3
if 0.50 moles of O3 reacted then,by use of reacting ratio (2:3) find the moles of O2 produced
That is 0.50 x3/2 = 0.75 moles
