Answer:
37.5 mL of a 4.0 M Mg(OH)₂ are needed to make 750 mL of 0.2 M Mg(OH)₂
Explanation:
Dilution is the reduction in concentration of a chemical in a solution. Dilution consists of lowering the amount of solute per unit volume of solution.
In other words, dilution is the procedure followed to prepare a less concentrated solution from a more concentrated one, and consists of adding solvent to an existing solution. The quantity or mass of the solute is not changed but only that of the solvent.
In dilutions the expression is used:
Ci*Vi = Cf*Vf
where:
- Ci: initial concentration
- Vi: initial volume
- Cf: final concentration
- Vf: final volume
In this case:
- Ci: 4 M
- Vi: ?
- Cf: 0.2 M
- Vf: 750 mL
Replacing:
4 M* Vi= 0.2 M* 750 mL
Solving:
Vi= 37.5 mL
<u><em>37.5 mL of a 4.0 M Mg(OH)₂ are needed to make 750 mL of 0.2 M Mg(OH)₂</em></u>
Answer:
because of the substance contained in a fire extingudher it woulfnt start a fire.
When the cows eat the grass
Answer:
The question is not complete as it lacks the options. The options are;
A) i,ii, and iii
B) i and ii
C) i,iii,and iv
D) i,ii,iii, and iv
E) iii and iv
The answer is A.
Explanation:
A redox reaction i.e. oxidation-reduction is a reaction in which a change in the oxidation number or state of the participating atoms occur. A redox reaction, as the name implies, contains the oxidation part and the reduction part.
Just like any other reaction, redox reaction needs to be balanced as well. A balanced redox reaction must have the following characteristics:
- The same number of each type of atom on both sides of the equation. For example, if there are 4 atoms of Carbon on the reactant side, there must be 4 atoms of C on product side.
- The total number electrons lost in the oxidation equal to total number of electrons gained in the reduction. For example, if 12 electrons are gained in the reduction part, 12 electrons must be lost in the oxidation part.
- The same total charge of all ionic species on both sides of the reaction.
<u>Answer:</u> The wavelength of an electron is
<u>Explanation:</u>
To calculate the wavelength of a particle, we use the equation given by De-Broglie's wavelength, which is:
where,
= De-Broglie's wavelength = ?
h = Planck's constant =
m = mass of electron =
v = velocity of electron =
Putting values in above equation, we get:
Hence, the wavelength of an electron is