1. What is the empirical formula of a compound which is made up of 37.5% carbon, 12.5% hydrogen, and the rest made up of oxygen.
2. Sodium reacts with water producing sodium hydroxide and hydrogen gas.
(a) Write the equation for the reaction.
(b) What volume of hydrogen is produced at r.t.p. when 0.2 mol of sodium reacts?
3. The reaction between hydrochloric acid and calcium carbonate is shown.
2HCl + CaCO3 → CaCl2 + H2O + CO2
What volume of 1M hydrochloric acid is needed to react completely with 1.0g of calcium carbonate?
4. Propane burns completely in oxygen according to the equation shown
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l)
If 0.1 mol of propane gas is burnt completely, what volume of gaseous product is obtained, measured at room temperature and pressure?
5. What mass of calcium oxide could be obtained by heating 25g of CaCO3.
CaCO3 → CaO + CO2
6. Hydrocarbons A and B both contain 85.7% carbon and 14.3% hydrogen.
(a) Find the empirical formula of A and B
(b) Find the molecular formula of A and B if the molecular mass (Mr) of A is 42 g and the molecular mass of B is 84.
7. What is the percentage yield of the reaction if 51 kg of aluminium oxide produced 17 kg of aluminium?
2Al2O3(l) → 4Al(l) + 3O2(g)
8. A 4.0g sample of dry ice (solid CO2) turned into 1900cm3 of carbon dioxide gas at rtp. What was the percentage purity of the dry ice?
9. What volume of ammonia gas would be needed to produce 35 g of ammonium nitrate in the following reaction?
NH3(g) + HNO3(aq) → NH4NO3(aq)
10. What mass of magnesium would be needed to produce 150 cm3 of hydrogen?
Mg(s) + H2SO4(aq) → MgSO4(aq) + H2(g)
點做? 比埋step plz
天日考 thx作者: 〝Ex喵﹑ 時間: 12-1-19 12:03 AM
睇唔明英文作者: 冷冷雨~WoWo 時間: 12-1-19 12:09 AM
〝Ex喵﹑ 發表於 12-1-19 12:03 AM
睇唔明英文
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全部都識做...
不過我聽日都要考試,無咁得閒幫你做
同埋其實題題都唔難.......作者: postpet40 時間: 12-1-19 12:26 AM
第1條係C H4 O methanol 作者: 冷冷雨~WoWo 時間: 12-1-19 12:29 AM
postpet40 發表於 12-1-19 12:26 AM
第1條係C H4 O methanol
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自己禁機
1. What is the empirical formula of a compound which is made up of 37.5% carbon, 12.5% hydrogen, and the rest made up of oxygen
let the compound be 100g
mass ratio C : H : O
mole ratio 37.5/12 12.5/1 (100-37.5-12.5)/16
: :
therefore, the empirical formula of the compound is ______________
2. Sodium reacts with water producing sodium hydroxide and hydrogen gas.
(a) Write the equation for the reaction.
(b) What volume of hydrogen is produced at r.t.p. when 0.2 mol of sodium reacts?
a)2Na + 2H2O > 2NaOH + H2 (METAL + WATER > METAL HYDROXIDE + HYDROGEN)
b)no of mole of Na= 0.2mol
no of mole of H2=0.1mol( ratio Na:H2= 2:1)
PV=nRT
V=nRT/P (R=8.31)
V=(0.1*8.31*(25+273))/1.01*10 ^3 8.31 , kPa, m3, mole, K(298)
V=___ m
V=____dm3
3. The reaction between hydrochloric acid and calcium carbonate is shown.
2HCl + CaCO3 → CaCl2 + H2O + CO2
What volume of 1M hydrochloric acid is needed to react completely with 1.0g of calcium carbonate?
no of mole of CaCO3 = 1/(40.1+12+16*3)= mol
no of mole of HCl = ____ X2 = mol
volume of 1M HCl =____X1 = dm3
4. Propane burns completely in oxygen according to the equation shown
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l)
If 0.1 mol of propane gas is burnt completely, what volume of gaseous product is obtained, measured at room temperature and pressure?
Refer to Q2
5. What mass of calcium oxide could be obtained by heating 25g of CaCO3.
CaCO3 → CaO + CO2
Refer to Q3
6. Hydrocarbons A and B both contain 85.7% carbon and 14.3% hydrogen.
(a) Find the empirical formula of A and B
(b) Find the molecular formula of A and B if the molecular mass (Mr) of A is 42 g and the molecular mass of B is 84.
比埋step plz
