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
60+68=128
128/2=64
so the answer is 64
I hope this helped
The simplest way to use the periodic table to identify<span> an </span>element<span> is by looking for the </span>element's<span> name or elemental symbol. The periodic table can be used to </span>identify <span>an </span>element<span> by looking for the </span>element's<span> atomic </span>number<span>. The atomic </span>number of<span> an </span>element<span> is the </span>number of<span> protons found within the atoms of that </span>element<span>.</span>
Answer:
the iron alone was dark brown and rectangular, whereas the iron-sulfur combination was a dark gray powder.
