Answer:
The volume of helium at 25.0 °C is 60.3 cm³.
Explanation:
In order to work with ideal gases we need to consider absolute temperatures (Kelvin). To convert Celsius to Kelvin we use the following expression:
K = °C + 273.15
The initial and final temperatures are:
T₁ = 25.0 + 273.15 = 298.2 K
T₂ = -196.0 + 273.15 = 77.2 K
The volume at 77.2 K is V₂ = 15.6 cm³. To calculate V₁ in isobaric conditions we can use Charle's Law.
Answer:
There are 1.05 x 10²⁴ molecules in 48.6 g N₂
Explanation:
1 mol of N₂ has a mass of (14 g * 2) 28 g.
Then, 48.6 g of N₂ will be equal to (48.6 g *(1 mol/ 28 g)) 1.74 mol.
Since there are 6.022 x 10²³ molecules in 1 mol N₂, there will be
(1.74 mol *( 6.022 x 10²³ / 1 mol)) 1.05 x 10²⁴ molecules in 1.74 mol N₂ (or 48. 6 g N₂).
Q1. TI (210/81Thallium)
Q2.
The answers are opposite from each other
Answer:
= 25 ppm
Explanation:
- PPM also refers to parts per million, it represents a low concentration of a solution. It represents 0.001 gram or a milligram in a 1000 mL, which equivalent to 1 mg per liter.
Given; a sample size of 2000 g contained 0.050 g DDT
It means, 2000 mL sample contained 50 mg DDT
Therefore in ppm we get;
= 50 mg/ 2 L
= 25 mg/L
<u>= 25 ppm</u>
The equivalence point of a titration is equal to its stoichiometric equivalents of analyte and titrant.
Depending on the concentration of titrant we could be adding little excess of it and this may result in persistence of color of solution. After continuous stirring for a while the excess titrant may react with dissolved CO₂ in air and thus decolorizing the solution.
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