To solve this problem, we need to set-up algebraic expression. First, use variables to represent the number of beads.
Let: x = number of Xavier's beads
y = number of Y<span>aozhou's beads
z = number of Zara's beads
</span>It is important to note that since we have three unknowns, we should also have three independent equations. <span>Based on the given statements, we have the following three equations:
(1) x + y = 438
(2) x + z = 204
(3) y = 3z
Substitute y in terms of z in equation (1). Then multiply equation (2) with -1.
x + 3z = 438
-(x + z = 204)
-------------------
2z = 234
z = 117
From equation (3),
y = 3(117) = 351
Using equation (1),
x = 438 - 351 = 87
Thus, Xavier had 87 beads.</span>
Answer:
The mass of reactants and products for the reaction is this:
- 92 g Na, 32 g O₂, 124 g Na₂O
which is not a choice from the list.
Explanation:
4 moles of Na reacts with 1 mol of oxygen to produce 2 moles of sodium oxide.
Na = 23 g/m
4 moles are (4 . 23) = 92 g
O₂ = 32 g/m
It's a diatomic molecule (each O is 16 g/m)
Na₂O = 62 g/m
2 mol of sodium oxide will be (2 .62) = 124 grams
The mass of reactants and products for the reaction is this:
- 92 g Na, 32 g O₂, 124 g Na₂O
which is not a choice from the list.
Answer:
-20 kcal/mol
Explanation:
In a reaction, enzymes reduces the energy of activation, but they have no effect on the Gibb's free energy of reaction. The free energy of the product is the same as it would be without the enzyme. Thus, the enzyme does not affect the free energy of the reaction. Mathematically
Gibb free energy = Enthalpy - temperature x change in entropy
Note that from the relation above, enzyme is not a factor nor is activation energy a factor.
As you move from left to right on the periodic table, atomic size and electronegativity increase.
(Ionization energy increases from left to right on the periodic table, and electronegativity relates to ionization energy in that the higher the ionization energy, the higher the electronegativity.)
(Atomic radius increases from left to right on the periodic table due to the fact that electrons are gradually being added from left to right, meaning the amount of protons in the nucleus are increasing in order to keep the atom neutral, therefore atomic size/radius increases.)
Answer is: ion product for strontium chromate is 3·10⁻⁵.<span>
Balanced chemical reaction (dissociation) of
strontium chromate:
</span>Sr²⁺(aq) + CrO₄²⁻(aq) → SrCrO₄.<span>
Qsp(</span>SrCrO₄) = c(Sr²⁺)·(CrO₄²⁻).<span>
c(</span>Sr²⁺) = 2.00·10⁻² M.
c(CrO₄²⁻) = 1.50·10⁻³ M.
Q = 2.00·10⁻² M · 1.50·10⁻³ M.
Q = 0.00003 = 3·10⁻⁵ M².
