Compounds Na₂SO₄ and NaCl are mixed together are we are asked to find the concentration of Na⁺ in the mixture
Na₂SO₄ ---> 2 Na⁺ + SO₄³⁻
1 mol of Na₂SO₄ gives out 2 mol of Na⁺ ions
the number of Na₂SO₄ moles added - 0.800 M/1000 * 100 ml
= 0.08 mol
therefore number of Na⁺ ions from Na₂SO₄ = 0.08 * 2 = 0.16 mol
NaCl ----> Na⁺ + Cl⁻
1 mol of NaCl gives 1 mol of Na⁺ ions
number of NaCl moles added = 1.20 M/1000 * 200 ml
= 0.24 mol
number of Na⁺ ions from NaCl = 0.24 mol
total number of Na⁺ ions in the mixture = 0.16 mol + 0.24 mol = 0.4 mol
as stated the volumes are additive,
therefore total volume = 100 ml + 200 ml = 300 ml
the concentration of Na⁺ ions = number of moles / volume
= 0.4 mol/ 0.3 dm³
concentration of Na⁺ = 1.33 mol/dm³
Answer:
6.53g of K₂SO₄
Explanation:
Formula of the compound is K₂SO₄
Given parameters:
Volume of K₂SO₄ = 250mL = 250 x 10⁻³L
= 0.25L
Concentration of K₂SO₄ = 0.15M or 0. 15mol/L
Unknown:
Mass of K₂SO₄ =?
Methods:
We use the mole concept to solve this kind of problem.
>>First, we find the number of moles using the expression below:
Number of moles= concentration x volume
Solving for number of moles:
Number of moles = 0.25 x 01.5
= 0.0375mole
>>Secondly, we use the number of moles to find the mass of K₂SO₄ needed. This can be obtained using the expression below:
Mass(g) = number of moles x molar mass
Solving:
To find the molar mass of K₂SO₄, we must know the atomic mass of each element in the compound. This can be obtained using the periodic table.
For:
K = 39g
S = 32g
O = 16g
Molar mass of K₂SO₄ = (39x2) + 32 + (16x4)
= 78 +32 + 64
= 174g/mol
Using the expression:
Mass(g) = number of moles x molar mass
Mass of K₂SO₄ = 0.0375 x 174 = 6.53g
Answer : The correct option is, 0.21 moles
Solution : Given,
Molarity of the solution = 0.85 M = 0.85 mole/L
Volume of solution = 250 ml = 0.25 L 
Molarity : It is defined as the number of moles of solute present in one liter of the solution.
Formula used :
Now put all the given values in this formula, we get the moles of solute of the solution.
Therefore, the moles of solute is, 0.21 moles
Answer:
False
Explanation:
While chemical reactions can proceed in the forward direction , they can in fact also proceed in the backward direction too. The direction they would proceed depends majorly on the state of chemical equilibrium at that particular time for that particular chemical reaction.
It should be known that when a chemical reaction proceeds in the forward way, more products are formed and the reactants are used up. If however, the chemical reaction proceed in the backward way, more reactants are formed and the products are used up.
A practical example is in the case of an exothermic reaction. This is one in which heat is released to the surroundings as a result of the reactants being at a higer energy level compared to the product. Now, depending on the prevailing equilibrium constraint, the reaction could proceed forward or backward.
If for example, the temperature is decreased, this is a constraint being applied to the equilibrium state. The chemical reaction would take a shift and will favor the forward reaction and more of the products will be formed. And also of the temperature is increased, it is the backward reaction that is favored
Answer : A metal atom loses electrons from its outermost energy level and acquires a Positive Charge. These electrons join a nonmetal atom. The ionic compound formed because of this transfer of electrons is electrically Neutral.
Explanation :
All the elements try to acquire octet state by gaining or losing electrons. For metals, the number of valence electrons are less and it is easier to lose these electrons.
When electrons are lost, the number of protons become more than the electrons. This creates an excess of positive charge. As a result the species becomes positively charged and is known as cation.
During formation of ionic bond, metals always form a positive ion (cation) by losing electrons. These electrons are accepted by the nonmetals and they become negatively charged. A negatively charged ion is known as anion and nonmetals always form an anion.
These are attracted to each other due to the opposite charges present on them. In an ionic compound they balance the charges on each other making the compound neutral.
From the above discussion, we can fill in the blanks as follows.
A metal atom loses electrons from its outermost energy level and acquires a Positive Charge. These electrons join a nonmetal atom. The ionic compound formed because of this transfer of electrons is electrically Neutral.
