Answer:
1. Exothermic.
2. Yes, released.
3. 38.65KJ of heat is released.
Explanation:
The equation for the reaction is given below:
2NO2 —> N2O4...... ΔH = –55.3KJ
1. The sign of the enthalpy change, ΔH tells whether the reaction is endothermic or exothermic. Since the sign of the enthalpy change, ΔH is negative, the reaction is exothermic.
2. The negative sign indicate that heat is released to the surrounding. Since the reaction is generally an exothermic reaction, 64.3g of NO2 will also release heat to the surroundings.
3. Molar mass of NO2 = 14 + (16x2) = 46g/mol
Mass of NO2 from the balanced equation = 2 x 46 = 92g.
From the balanced equation above:
92g of NO2 reacted to release –55.3KJ of heat.
Therefore, 64.3g of NO2 will react to release = (64.3 x –55.3)/92 = 38.65KJ of heat.
Therefore, 38.65KJ of heat is released.
Answer:
it helps by improving blood circulation, replacing the bodies electrolytes, detoxifying the body, and boosting bone mineral density.
Explanation:
Answer:
n=5
Explanation:
Applying the Rydberg's equation
hc/l= RH[(1/nf^2)-(1/ni^2)
Let l= wavelength= 3745×10^-9m
h=6.63×10^-34 , c= 3.0×10^8, RH= 2.179×10^-18
Substitute into the Rydberg's equation and simplify
(6.63×10^-34×3×10^8)/3745×10^-9=2.179×10^-18(1/nf^2 -1/8^2)
0.024= 1/nf^2 -0.0156
0.024+0.0156= 1/nf^2
0.0396= 1/nf^2
nf^2= 25.3
Take square root of both sides
nf= 5.02=5
Answer:
The measured absorbance will be too large.
Explanation:
Fe³⁺(aq) + SCN⁻(aq) ⟶Fe(SCN)²⁺(aq)
A = log₁₀(I₀/I)
If the student orients the cuvette so that the path of the light is through the frosted sides of the cuvette, little light will be able to reach the detector.
The measured intensity (I) will be quite small, so the absorbance (A) will be unusually large.
Answer:
Molarity of dextrose = 0.03 mol / L
Explanation:
Given data
mass of dextrose = 5 g
Concentration (Molarity) = ?
Solution
as mass is given so we find out number of moles
<em>Moles = mass / molar mass</em>
Molar mass of dextrose = 180.156 g/mol
Moles = 5 g / 180.156 g/mol
Moles = 0.03 moles
Now we find out molarity
<em>Molarity = moles of solute / Litres of solution</em>
As volume is not given so we suppose it as 1 L
Molarity of dextrose = 0.03 mol / 1 L
Molarity of dextrose = 0.03 mol / L