Hey there!
mass of sample = 2.51 g of Aspirin
Number of moles of base ( NaOH ) :
M*V = 27.36*0.5106 = 13.9700 mmol of base
M*V = 13.68*0.516 = 7.05888 mmol of acid
pKa calculation:
pH = pKa + log(A-/HA)
3.48 = pKa + log(7.05888 / (13.9700 -7.05888))
Pka =3.49 - log(7.05888 / (13.9700 -7.05888))
pKa = 3.48
Molar mass calculation:
molar mass = mass/mol
(2.51)/(13.9700 *10⁻³) =
molar mass 180 g/mol approx
Hope that helps!
Answer: heat
Explanation:
Infrared radiation is popularly known as "heat radiation",[21] but light and electromagnetic waves of any frequency will heat surfaces that absorb them. Infrared light from the Sun accounts for 49%[22] of the heating of Earth, with the rest being caused by visible light that is absorbed then re-radiated at longer wavelengths
Answer;
D, Xe (g)
Solution and explanation;
If 2g has a volume of 340ml.
Density is 1000/340*2 = 5.88g/litre.
-This rules out the two solids, choices 2) &3)
If 1 litre has mass 5.88g,
then 22.4 liters (volume at STP) has mass 5.88*22.4 = 131.8g/mol
molar mass Br2 = 80*2 = 160g/mol NO
molar mass Xe = 131.3g/mol = YES.
Answer is Xe
Answer is: formula of hydrate is CoCl₂· 6H₂O -c<span>obalt(II) chloride hexahydrate
</span>m(CoCl₂· xH₂O) = 1,62 g.
m(CoCl₂) = 0,88 g.
n(CoCl₂) = m(CoCl₂) ÷ M(CoCl₂)
n(CoCl₂) = 0,88 g ÷ 130 g/mol
n(CoCl₂) = 0,0068 mol.
m(H₂O) = 1,62 g - 0,88 g.
m(H₂O) = 0,74 g.
n(H₂O) = m(H₂O) ÷ m(H₂O)
n(H₂O) = 0,74 g ÷ 18 g/mol
n(H₂O) = 0,041 mol.
n(CoCl₂) : n(H₂O) = 0,0068 mol : 0,041 mol.
n(CoCl₂) : n(H₂O) = 1 : 6.
