Answer:
20.5 × 10²³ molecules of He
Explanation:
Given data:
Number of moles of He = 3.40 mol
Number of molecules of He = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 3.40 moles of He:
3.40 mol × 6.022 × 10²³ molecules
20.5 × 10²³ molecules of He
Answer:
1.24x10⁻⁴ mol/L
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Explanation:
5 ppm is a sort of concentration that indicates:
weigh of solute x 10⁶ / weigh of solution or volume of solution.
Relation must be in the order of 10⁻⁶, for example mg/kg / μg/g.
We can also write ppm as μg/mL, so 5 ppm will be understood as 5 μg of Ca²⁺ in 1mL of solution.
This would be the rule of three to reach molarity
In 1mL we have 5 μg of Ca²⁺
In 1000 mL we would have 5000 μg of Ca²⁺
Let's convert 5000 μg to g ( 1g = 1x10⁶μg)
5000 μg = 5x10⁻³ g
Now, that we have the mass, we convert it to moles (mass / molar mass)
5x10⁻³ g / 40.08g/m = 1.24x10⁻⁴ moles
As this moles are in 1000mL (1L) it's molarity
Answer:
2450000 gram
Explanation:
v= m × ρ= 1 cubic meter × 2.45 gram/cubic centimeter= 1000000 cubic centimeter × 2.45 gram/cubic centimeter= 2450000 gram
Farm water runoff, which causes nitrogen rich fertilizer to be washed into the body of water. The nitrogen feeds the algae bloom.. Hope this helps
Answer: Element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron
Explanation:a b d