Answer:
0,12 μmol/L of MgF₂
Explanation:
Preparation of solutions is a common work in chemist's life.
In this porblem says that you measure 0,00598 μmol of MgF₂ in 50,0 mL of water and you must calculate concentration in μmol/L
You have 0,00598 μmol but not Liters.
To obtain liters you sholud convert mL to L, knowing 1000mL are 1 L, thus:
50,0 mL (1L/1000mL) = 0,05 L of water.
Thus, concentration in μmol/L is:
0,00598 μmol / 0,05 L = 0,12 μmol/L -The problem request answer with two significant digits-
I hope it helps!
Answer:

Explanation:
We are asked to find the density of a metal. Density is the mass per unit volume. It is calculated by dividing the mass by the volume.

The mass of the metal sample is 24.64 grams and the volume is 5.91 milliliters. We can substitute these values into the formula.

Divide.

The mass measurement has 4 significant figures the volume measurement has 3 significant figures. Our answer for density must match the least number of significant figures, which is 3.
For the number we calculated, that is the hundredth place. The 9 in the thousandth place tells us to round the 6 up to a 7.

The density of this metal is approximately <u>4.17 grams per milliliter.</u>
<u>Answer:</u>
Density is mass per unit volume.
Its formula is
Density = Mass / Volume
Its units can be kg/L or kg/(
) or g/mL or g/(
)
Density of various substances are given. The more denser substance goes to the bottom of the graduated cylinder.
Air on the top then comes Wood followed by Corn oil followed by Ice and then Water followed by Glycerin then Rubber then Corn syrup and at last Steel at the bottom which will more denser than all the substances mentioned above.
The staking up of the substances is in the order mentioned below in the tabular column
Search ggl because we cannot add picture here.
Molarity is defined as the ratio of number of moles to the volume of solution in litres.
The mathematical expression is given as:

Here, molarity is equal to 1.43 M and volume is equal to 785 mL.
Convert mL into L
As, 1 mL = 0.001 L
Thus, volume =
= 0.785 L
Rearrange the formula of molarity in terms of number of moles:

n = 
= 1.12255 mole
Now, Number of moles = 
Molar mass of potassium hydroxide = 56.10 g/mol
1.12255 mole = 
mass in g =
= 62.97 g
Hence, mass of
= 62.97 g