Answer:
4 energy levels/rings
Explanation:
By the atomic model proposed by Niels Bohr, the electrons orbit around the nucleus in shells having different energy level each with the ability to contain a given maximum amount of electrons.
The closest shell to the nucleus named the K shell, can have a maximum of two electrons, the next shell known as the L shell can have 8 electrons while the next shell, M, can have a maximum of 18 electrons
The arrangement of the periodic table is based on the number and location of electrons such that elements in the 4th row (period 4 elements) have three completed energy levels/rings before, their valence ring making the total number of rings = 4 energy levels/rings.
Answer:
62.36 g
Explanation:
AgNO3 + H2SO4 - > Ag2SO4 + HNO3
The balanced equation is given as;
2AgNO3 + H2SO4 → Ag2SO4 + 2HNO3
From the equation;
2 mol of AgNO3 reacts with 1 mol of H2SO4
if 0.200 moles of AgNO3 react with 0.155 moles of H2SO4
The limiting reactant us AgNO3 as it determines the amount of products to be formed.
2 mol of AgNO3 produces 1 mol of Ag2SO4
0.2 mol of AgNO3 would produce x mol of Ag2SO4
Solving for x;
2 = 2
0.2 = x
x =0.2 * 2/ 2 = 0.2 mol
Converting moles to mass;
Mass = Number of Moles * Molar mass
Mass = 0.2 mol * 311.8 g/mol
Mass = 62.36 g
Answer: The standard potential is -0.141 V
Explanation:
To calculate the Gibbs free energy for given value of equilibrium constant we use the relation:
where,
= standard Gibbs free energy = ?
R = Gas constant = 8.314 J/Kmol
T = temperature = 298 K
K = equilibrium constant =
Putting values in above equation, we get:
Also
where n = no of electrons gained or lost = 3
F = Faradays constant = 96500 C
= standard potential = ?
Thus the standard potential is -0.141 V
This problem uses the relationship between Kb and the the dissociation constants which is expressed as Kw = KaKb. Calculations are as follows:
<span>
Kb = KaKb
</span><span>1.00 x 10^-14 = 7.2 x 10^-4(x)
</span><span>x = 1.39 x 10^-11
</span><span>
We now need to calculate the [OH¯] using the Kb expression:
</span>1.39 x 10^-11 = x^2 / (0.30 - x)
<span>
The denominator can be neglected. </span><span>Thus, x is 3.73 x 10^-6.
</span><span>
pOH = -log 3.73 x 10^-6 = 5.43
p</span><span>H = 14-5.43 = 8.57</span>
Answer:
Enzymes are homogenous, thermolabile,biological catalyst that increases the reaction rate of a chemical reaction.
Explanation:
Enzymes are used as catalyst in many biochemical reactions.Enzymes basically interact in a complementary fashion with the transition state of the reaction thus helping to decrease the energy barrier called activation energy.Thus enzymes helps to stimulate the velocity of biochemical reaction.
It is very important point to note that enzymes do not affect the reaction equilibrium.