Answer:
0.0025moles
Explanation:
Molarity of a solution (M) = number of moles (n) ÷ volume (V)
According to this question, to make 250 mL of a 0.01 M solution of CaCl, the following number of moles is needed:
Volume = 250mL = 250/1000 = 0.250Litres.
Using; molarity = n/V
0.01 = n/0.250
n = 0.0025
n = 2.5 × 10^-3 moles.
<span>In H2CO, C is bonded to H, H and O. Write down the valence electrons of each element.
2 H = 1x 2 = 2.
C= 4
O = 6
Total 12 </span>
D) They both look uniform (the same) throughout.
<h3>Further explanation</h3>
Pure substance can be any element or compound and is formed from one type of atom/molecule only
Meanwhile, the solution is included in a mixture consisting of 2 or more pure substance
Pure substance can be formed through a chemical process while the mixture is through a physical process
Mixture can be separated by physical processes into components of pure substance while pure substance cannot
The mixture itself consists of a homogeneous and heterogeneous solution
The mixture can be divided into a homogeneous mixture if the composition/ratio of each substance in the mixture is the same and a heterogeneous mixture if the ratio of the composition of the substances is not the same (can be varied) in each place.
Mixtures can also be divided into solutions, suspensions, and colloids based mainly on the size of the particles
Homogeneous mixture = Solution
Heterogeneous mixture = suspension, and
The mixture is located between suspension and solution = Colloid
3 Chlorine ions are required to bond with one aluminum ion.
In ionic bonds, metals atoms loses all its outermost shell electrons to form a cation. While, non metal atoms gains however many electrons in order to make its outermost electron shell be 8 (or 2 if there's only one shell).
Therefore, form the periodic table, we can see that aluminum has a atomic number of 13, which makes its electron arrangement be 2,8,3. So, in order to form a aluminum ion, an Al atom must lose 3 electrons. On the other hand, Chlorine has a atomic number of 17, which means it has the electron configuration of 2,8,7. It has to gain only 1 electron to have 8 outermost shell electron.
Thereofre, 3 Chlorine atom are required to gain all 3 electrons given out by just 1 aluminum ion.
