Answer:
Q = 306 kJ
Explanation:
Given that,
Mass, m = 60 kg
Specific heat, c = 1020 J/kg°C
The temperature changes from 20°C to 25°C.
Let Q be the change in thermal energy. The formula for the heat released is given by :
Put all the values,
So, 306 kJ is the change in thermal energy.
Answer:
The top layer is the Aqueous layer, and the benzoic acid is contained in the non-aqueous layer/oil phase.
Explanation:
A separating funnel is a very important piece of laboratory glassware that is used to separate the components of liquid-liquid mixtures which are immiscible. This technique is used in the extraction of the components of mixtures.
The liquids separate into two phases. The separation is based on the differences in the liquids' densities, where the denser liquid settles below and the lower density liquid stays afloat. Liquids used for this kind of separation are usually different liquids, one is the aqueous layer and the other, a non-aqueous layer.
Partition coefficient or distribution coefficient is defined as the ratio of the concentrations of a compound in two immiscible solvents at equilibrium.
Organic solvents (except halogenated organic compounds) with densities greater than that of water i.e 1g/mL ( usually called the oil phase) settle at the bottom of the aqueous phase.
Benzoic acid. will settle at the bottom layer ( i.e the lower phase).
Ok measure atoms the answer is B
The answer is 4.9 moles.
Solution:
Using the equation for boiling point elevation Δt,
Δt = i Kb m
we can rearrange the expression to solve for the molality m of the solution:
m = Δt / i Kb
Since we know that pure water boils at 100 °C, and the Ebullioscopic constant Kb for water is 0.512 °C·kg/mol,
m = (105°C - 100°C) / (2 * 0.512 °C·kg/mol)
= 4.883 mol/kg
From the molality m of the solution of salt added in a kilogram of water, we can now find the number of moles of salt:
m = number of moles / 1.0kg
number of moles = m*1.0kg
= (4.883 mol/kg) * (1.0kg)
= 4.9 moles
<span>E=hν</span> where E is the energy of a single photon, and ν is the frequency of a single photon. We recall that a photon traveling at the speed of light c and a frequency ν will have a wavelength λ given by <span>λ=<span>cν</span></span>λ will have an energy given by <span>E=<span><span>hc</span>λ</span></span><span>λ=657</span> nm. This will be <span>E=<span><span>(6.626×<span>10<span>−34</span></span>)(2.998×<span>108</span>)</span><span>(657×<span>10<span>−9</span></span>)</span></span>=3.0235×<span>10<span>−19</span></span>J</span>
So we now know the energy of one photon of wavelength 657 nm. To find out how many photons are in a laser pulse of 0.363 Joules, we simply divide the pulse energy by the photon energy or <span>N=<span><span>E<span>pulse </span></span><span>E<span>photon</span></span></span>=<span>0.363<span>3.0235×<span>10<span>−19</span></span></span></span>=1.2×<span>1018</span></span>So there would be <span>1.2×<span>1018</span></span><span> photons of wavelength 657 nm in a pulse of laser light of energy 0.363 Joules.</span>
