Molar mass NaCl = 58 g
Mass of solute = 29 g
number of moles: mass of solute / molar mass
n = 29 / 58
n = 0.5 moles
hope this helps!
Answer:
Lewis dot diagrams use dots arranged around the atomic symbol to represent the electrons in the outermost energy level of an atom
Explanation:
42.34 g of water could be warmed from 21.4°C to 43.4°C by the pellet dropped inside it
Heat loss by the pellet is equal to the Heat gained by the water.
….(1)
where, 
is the heat gained by water
is the heat loss by pellet
= mCΔT
where m = mass of water
C = specific heat capacity of water = 4.184 J/g-°C
ΔT = Increase in temperature
ΔT for water = 43.4 - 21.4 = 22°C
= m × 4.184 × 22 …. (2)
Now
= 
×ΔT
where = Heat capacity of pellet = 56J/°C
Δ T for pellet = 43.4 - 113 =- 69.6°C
= 56 × -69.6 = -3897.6 J
From equation (1) and (2)
-m× 4.184 × 22 =-3897.6
m= 42.34 g
Hence, 42.34 g of water could be warmed from 21.4 degrees Celsius to 43.4 degrees Celsius by the pellet dropped inside it.
Learn more about specific heat here brainly.com/question/16559442
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We know that:
f * λ = c
<span>and
E = h*f
so,rearranging:
</span>
<span>E/h = C/λ
given:
h = </span><span>6.90 × 10^2 nm
</span><span>substituting the values:
E = </span> C/λ<span> x h
(c is the speed of light;that is 3x10^8 m/s)
</span> = 3x10^8 x 6.626x10^-34 / 6.90 x10^7m x 6.022x10^23
Hence,
using calculator:
we get,
E = 1.69 x 10^5 Joules
