Answer:
The ΔH of the reaction is + 12.45 KJ/mol
Explanation:
Mass of water= 100ml = 100g. (You should always assume 1cm3 of water as 1g)
heat capacity of water = 4.18 Jk-1 Mol-1
Change in temperature = (19.86 - 25.00) = -5.14 K (This is an endothermic reaction because of the fall in temperature)
Molar mass of NaHCO3 = 84 g/mol
Mole of NaHCO3 = 14.5 / 84 = 0.173 mol
Step 1 : Calculate the heat energy (Q) lost by the water.
Q = M x C x ΔT
Q = -100 x 4.18 x (-5.14)
Q = 2148.5 joules
Q = 2.1485 K J
Step 2: Calculating the ΔH of the reaction?
ΔH = Q / number of moles of NaHCO3
ΔH = 2.1485 / 0.173
ΔH = 12.42 KJ/mol
Answer:
547.5g
Explanation:
To get the mass, you need moles.
moles = (molarity)(Liters)
moles = (1.230M)(4.200L) = 5.166 moles Na2CO3
Now, just use stoichiometry
molar mass of Na2CO3 = 2(mass of Na) + (mass of C) + 3(mass of O)
= 2(22.9) + 12.01 + 3(16) = 105.99g/mol
5.166moles(105.99g/mol)
= 547.544
But, the measurements given had 4 significant figures, so in chemistry we write:
547.5g
Answer:
im not completely sure but the mst likely answer would be the would be they have the same density
Explanation:
if two mixture have the same ingriedients their most likely going to have the same density depending of the measurements like when baking a cake when you add your wet ingriedients to your dry one it makes a batter and if you were to make another mixture with the same ingriedients and somewhat similar measurements your going to get a similar density
It's a weak base bacause H C N is weak
Answer: Benzene is less reactive than methylbenzoate and more reactive than Nitrobenzene
Explanation:
This is because the methyl group on the benzene ring is an electron donating group leading to the activation of the ring and subsequently leading to more canonical resonance structure at the intermediate stage of the reaction enhancing the faster reactivity
However for the Nitrobenzene the nitro group is an electron withdrawing group leading to a slower activation and less resonance canonical structure at the reaction intermediate leading to a slower reaction than the reaction of benzene without the nitro group
