Answer:
Explanation:
mole of NaOH present = molarity x volume
= 1.0 X 0.05 = 0.05 mole
<em>Recommended mole of HCl </em>= 1.1 x 0.05 = 0.055
<em>Mole of HCl carelessly added by Jacob </em>= 1.1 x 0.04 = 0.044
From the equation of reaction:
HCl + NaOH ----> NaCl + H2O
The ratio of mole of HCl to that of NaOH for a complete neutralization reaction is 1:1. However, the recommended mole of HCl (0.055 mole) is more than the mole of NaOH (0.05 mole). <u>Hence, the recommended endpoint of the reaction is supposed to be acidic.</u>
The mole of HCl added by Jacob (0.044) is short of the recommended amount (0.055) and also short of the amount required for a neutral endpoint (0.05). <u>This means that the endpoint will have an excess amount of NaOH and as such, basic instead of the desired acidic endpoint.</u>
Answer:
The thermal energy (heat) needed, to raise the temperature of oil of mass 'm' kilogram and specific heat capacity 'c' from 20°C to 180°C is 160·m·c joules
Explanation:
The heat capacity, 'C', of a substance is the heat change, ΔQ, required by a given mass, 'm', of the substance to produce a unit temperature change, ΔT
∴ C = ΔQ/ΔT
ΔQ = C × ΔT
C = m × c
Where;
c = The specific heat capacity
ΔT = The temperature change = T₂ - T₁
∴ ΔQ = m × c × ΔT
Therefore, the thermal energy (heat) needed, ΔQ, to raise the temperature of oil of mass 'm' kilogram and specific heat capacity, 'c' from 20°C to 180°C is given as follows;
ΔQ = m × c × (180° - 20°) = 160° × m·c
ΔQ = 160·m·c joules
Answer:
- <em>2NaCl → 2Na + Cl₂, ΔH = 822 kJ </em>
Explanation:
The chemical <em>equation</em> for the <em>formation of NaCl</em> is:
- Na + (1/2) Cl₂ → NaCl , ΔH = - 411 kJ
That equation means that 1 mole of NaCl is formed by the reaction of 1 mole of Na and 1/2 mole of Cl₂, with a release of energy of 411 kJ.
The <em>decomposition</em> of <em>NaCl</em> is the inverse of the <em>formation</em> reaction; thus, you swift products and reactants and inverse the sign of the <em>change in enthalpy:</em>
- NaCl → Na + 1/2 Cl₂, ΔH = 411 kJ
Since you want the decomposition of 2 moles you multiply the equation and the ΔH by 2:
- 2NaCl → 2Na + Cl₂, ΔH = 822 kJ ← answer
Group 16 must gain 2 electrons to become stable as stated in my other answer
Hope this helped
Matter is made of very tiny particles. One mole of a substance contains a given amount of particles. This number is constant for all particles- 6.022×10^23<span> , and is called Avogadro's constant. To get the number of particles in 4g of butane, we need to calculate the number of moles represented by 4 g, then multiply by the Avogadro's constant (Since each mole has particles equivalent to the Avogadro's constant)
Therefore, if 1 mole = 58.1g
how many moles will be equal to 4g?
we cross multiply (4x1) divide by 58.1
equals 0.068847moles
multiply by Avogadro constant = 4.1466 x 10^molecules
But remember the question is not about the number of molecules in butane, its about the number of carbon atoms.
Since there are four carbons in butane, and each has </span> 4.1466 x 10^22 atoms
to get the number of atoms, we multiply by four
equals 1.6586 x 10^atoms
