The world's tallest artificial Christmas tree measured a mammoth 5.20 x 103 cm. How tall is the tree in kilometers?
1 answer:
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Answer:
0.0400 g for the example given below.
Explanation:
pH value is not provided, so we'll solve this problem in a general case and then we will use an example to justify it.
- By definition,
.
- NaOH is a strong base, as it's a hydroxide formed with a group 1A metal, so it dissociates fully in water by the equation:
.
- From the equation above, using stoichiometry we can tell that the molarity of hydroxide is equal to the molarity of NaOH:
.
- Concentration of hydroxide is then equal to the ratio of moles of NaOH and the volume of the given solution. Moles themselves are equal to mass over molar mass, so we obtain:
.
- We also know that
. Take the antilog of both sides:
.
- Solve for the mass of NaOH:
.
Now, let's say that pH is given as 12.00 and we use a 100-ml volumetric flask. Then we would obtain:
Answer:
Explanation:
Dado que:
masa de oxígeno gaseoso = 100 g
presión = 1 atm
temperatura = 273 K
(a)
número de moles de oxígeno contenidos en el matraz = masa de oxígeno / masa molar de oxígeno
= 100 g / 16 gmol⁻¹
= 6.25 moles
(b) El número de moléculas de oxígeno es el siguiente:
Dado que 1 mol de oxígeno gaseoso contiene 6.023 * 10²³ moléculas de oxígeno.
Entonces, 6.25 moles contendrán:
= (6.25 × 6.023 * 10²³) moléculas de oxígeno.
≅ 3.764 × 10²³ moléculas de oxígeno.
(c) El número de átomos de oxígeno es:
= 2 × 3.764 × 10²³
= 7.528 × 10²³ átomos de oxígeno
(d) Usando la ecuación de gas ideal
PV = nRT
El volumen ocupado por el oxígeno =
Volumen ocupado por oxígeno =
Volumen ocupado por oxígeno= 14185.76 m³