Answer:
B. 0.2.
Explanation:
<em>n = mass/molar mass</em>
mass of CaCO₃ = 20 g, molar mass of CaCO₃ = 100.0869 g/mol.
<em>∴ n = mass/molar mass = </em>(20 g)/(100.0869 g/mol) <em>= 0.1998 ≅ 0.2 mol.</em>
<em></em>
<em>So, the right choice is: B. 0.2.</em>
Mass is measured in kilograms.
Answer:
The number of stamps and cards Maggie has left if she gives 45 stamps to a friend is 183
Explanation:
If Maggie gives 45 stamps to a friend, you must calculate the number of stamps and cards she has left.
You know Maggie has 4 folders with 30 stamps in each folder. So the number of stamps she owns is calculated as:
4 folders*30 stamps in each folder= 120 stamps
If Maggie gives 45 stamps to a friend, then the number of stamps she has left will be calculated as the difference (the subtraction) between the stamps she owned and the ones she gives away:
120 stamps - 45 stamps= 75 stamps
On the other hand, she has 3 binders with 36 baseball cards in each binder. So the number of cards she owns is calculated as:
3 binders * 36 baseball cards in each binders= 108 baseball cards
The number of stamps and cards you have left is calculated as:
75 stamps + 108 baseball cards= 183
<em><u>The number of stamps and cards Maggie has left if she gives 45 stamps to a friend is 183</u></em>
0.300 M IKI represents the
concentration which is in molarity of a potassium iodide solution. This means
that for every liter of solution there are 0.300 moles of potassium iodide. Knowing
that molarity is a ratio of solute to solution.
By using a conversion factor:
100 ml x (1L / 1000 mL) x (0.300
mol Kl / 1 L) x (166.0g / 1 mol Kl) = 4.98 g
Therefore, in the first
conversion by simply converting the unit of volume to liter, Molarity is in L
where the volume is in liters. The next step is converted in moles from volume
by using molarity as a conversion factor which is similar to how density can be
used to convert between volume and mass. After converting to moles it is simply
used as molar mass of Kl which is obtained from periodic table to convert from
mole to grams.
In order to get the grams of IKI
to create a 100 mL solution of 0.600 M IKI, use the same formula as above:
100 ml x (1L / 1000 mL) x (0.600
mol Kl / 1 L) x (166.0g / 1 mol Kl) = 9.96 g
245 mm Hg = 32.6634 kPa
<u>Explanation:</u>
When the pressure inside the can is measured in mm Hg and it is needed to convert mm mercury (Hg) to kilo pascal, we have to multiply the pressure in mm Hg with 0.13332, so that the pressure is converted in kilo pascals.
1 mm Hg × 0.13332 = 1 kPa
245 mm Hg × 0.13332 = 32.6634 kPa
So the pressure in mm mercury is converted into kilo pascals.
