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
P * V = n R T
<span>1 * 2.50 = n * 0.082 * 273 = 2. 50 / ( 0.082 * 273 ) = 0.11 mol </span>
<span>mass = mole number * molecular mass </span>
<span>mass = 0.11 * ( 16 * 2 ) = 3.52 g </span>
Answer: 3 moles Na
Explanation: To find the number of moles of Na, divide the number of atoms of Na with the Avogadro's Number.
1.806x10²⁴ atoms Na x 1 mole Na / 6.022x10²³ atoms Na
= 2.99 or 3 moles Na
Answer:
A. They are malleable, ductile, and conduct electricity.
Explanation:
