The concentration after dilution is 1.4%.
We are aware that concentration and volume are related to each other by the formula -
=
, where we have initial concentration and volume on Left Hand Side and final concentration and volume on Right Hand Side.
Keep the values to calculate final concentration.
= (53.5 × 5.4)/205.0
Performing multiplication on Right and Side
= 288.9/205.0
Performing division on Right Hand Side
= 1.4%
Hence, the final concentration is 1.4%.
Learn more about concentration -
#SPJ4
The complete question is -
A 53.5 mL sample of an 5.4 % (m/v) KBr solution is diluted with water so that the final volume is 205.0 mL.
Calculate the final concentration and express your answer to two significant figures and include the appropriate units.
Formula units in 450 g of is 1.93 × 10²⁴ formula units.
<u>Explanation:</u>
First we have to find the number of moles in the given mass by dividing the mass by its molar mass as,
Now, we have to multiply the number of moles of Na₂SO₄ by the Avogadro's number, 6.022 × 10²³ formula units/mol, so we will get the number of formula units present in the given mass of the compound.
3.2 mol × 6.022 × 10²³ = 1.93 × 10²⁴ formula units.
So, 1.93 × 10²⁴ formula units is present in 450g of Na₂SO₄.
Answer:
Approximately 1.9 kilograms of this rock.
Explanation:
Relative atomic mass data from a modern periodic table:
To answer this question, start by finding the mass of Pb in each kilogram of this rock.
89% of the rock is . There will be 890 grams of
in one kilogram of this rock.
Formula mass of :
.
How many moles of formula units in that 890 grams of
?
.
There's one mole of in each mole of
. There are thus
of
in one kilogram of this rock.
What will be the mass of that of
?
.
In other words, the in 1 kilogram of this rock contains
of lead
.
How many kilograms of the rock will contain enough to provide 1.5 kilogram of
?
.