Answer:
B. The student chose the correct tile, but needs to flip the tile to make the units cancel
Explanation:
Based on the reaction:
2AgNO₃(aq) + Cu(s) → 2Ag(s) + Cu(NO₃)₂ (aq)
<em>2 moles of AgNO₃ react per mole of Cu producing 2 moles of Ag and 1 mole of Cu(NO₃)₂</em>
Thus, if you want to produce 6.75moles of Cu(NO₃)₂ you need:
= 13.50 moles of AgNO₃ are needed
Thus, if you analize the tile shown by the student:
<em>B. The student chose the correct tile, but needs to flip the tile to make the units cancel</em>
1) Compund Ir (x) O(y)
2) Mass of iridium = mass of crucible and iridium - mass of crucible = 39.52 g - 38.26 g = 1.26 g
3) Mass of iridium oxide = mass of crucible and iridium oxide - mass of crucible = 39.73g - 38.26g = 1.47g
4) Mass of oxygen = mass of iridum oxide - mass of iridium = 1.47g - 1.26g = 0.21g
5) Convert grams to moles
moles of iridium = mass of iridium / molar mass of iridium = 1.26 g / 192.17 g/mol = 0.00656 moles
moles of oxygen = mass of oxygen / molar mass of oxygen = 0.21 g / 15.999 g/mol = 0.0131
6) Find the proportion of moles
Divide by the least of the number of moles, i.e. 0.00656
Ir: 0.00656 / 0.00656 = 1
O: 0.0131 / 0.00656 = 2
=> Empirical formula = Ir O2 (where 2 is the superscript for O)
Answer: Ir O2
V1 = 2.0 L
T1 = 25.0 oC = 298 K V2 = V1T2 = (2.0 L)(244 K) = 1.6 L
V2 = ? t1(298 K)
T2 = –28.9 oC = 244 K
The new temperature : 11.56 °C
<h3>Further explanation </h3>
Boyle's law and Gay Lussac's law
P1 = initial gas pressure (N/m² or Pa)
V1 = initial gas volume (m³)
P2 = final gas pressure
V2 = final gas volume
T1 = initial gas temperature (K)
T2 = final gas temperature
V₁=4.39 L
T₁=44+273=317 K
P₁ = 729 torr = 0,959211 atm
V₂=3.78 L
P₂= 1 atm