Answer: CrO₄⁻ and Ba²⁺
Explanation:
1) Chemical equation given:
2H⁺ + CrO₄⁻ + Ba²⁺ + 2OH⁻ → Ba²⁺ + CrO₄⁻ + 2H₂O
2) Analysis
That is an oxidation-reduction equation (some species are been oxidized and others are being reduced).
The given equation is known as total ionic equation, because it shows all the species as ions that are part of the reaction.
2) Specator ions
Spectator ions are the ions that do not change their oxidation state and are easily identified as they are the same in the reactant and product sides.
Here the ions that are the same in the reactant and product sides are:
CrO₄⁻ and Ba²⁺
3) Addtitional explanation.
Once you identify the spectator ions you can delete them from the equation to obtain the net ionic equation , which in this case turns to be:
2H⁺ + 2OH⁻ → 2H₂O
But this is not part of the question; it is some context to help you understand the use of the spectator ions concept.
Answer:
The geologist time scale was formed when scientists studied rock layers and index fossils worldwide. With this information, they placed Earth's rocks in order by relative age. Later, radioactive dating helped determine the exact age of the divisons in the geologic time scale.
This scale is organized by the 4.6 billion years of earth's history into sections based on important changes seen in the geologic record. The largest intervals are called eons, with each eon containing many millions of years.
In precambarian time the processes that affect Earth's surface have lessened the erosion on the surface. Earth was being hit by meteorites every second. Now there is water erosion and there wasn't back then. The surface changes have lessened over time.
Answer:
Explanation:
<u>1. Equilibrium equation</u>
<u>2. Equilibrium constant</u>
The liquid substances do not appear in the expression of the equilibrium constant.
![k_c=\dfrac{[HBr(g)]^2}{[H_2]}=4.8\times 10^8M](https://tex.z-dn.net/?f=k_c%3D%5Cdfrac%7B%5BHBr%28g%29%5D%5E2%7D%7B%5BH_2%5D%7D%3D4.8%5Ctimes%2010%5E8M)
<u>3. ICE table.</u>
Write the initial, change, equilibrium table:
Molar concentrations:
H₂(g) + Br₂(l) ⇄ 2HBr(g)
I 0.400 0
C - x +2x
E 0.400 - x 2x
<u>4. Substitute into the expression of the equilibrium constant</u>
<u>5. Solve the quadratic equation</u>
- 192,000,000 - 480,000,000x = 4x²
- x² + 120,000,000x - 48,000,000 = 0
Use the quadratic formula:
The only valid solution is x = 0.39999999851M
Thus, the final concentration of H₂(g) is 0.400 - 0.39999999851 ≈ 0.00000000149 ≈ 1.5 × 10⁻⁹M
You can determine the hazards of these chemicals by looking at their material data safety sheets (MSDS).
1. 0.1 M Ag⁺: Silver compounds are absorbed by skin causing bluish pigmentation. Thus, it <em>causes </em><span><em>staining on skin</em>.</span> Also, liquid <em>vapor may be irritating</em> to skin and also <em>moderately toxic when ingested</em>.
2. 0.1 M Ba²⁺: This is <em>mildly toxic when ingested</em> causing stomach irritation, muscle weakness, swelling of organs like brain, liver, kidney and heart.
3. 0.1 M Fe³⁺:Iron is <em>corrosive, has irritating vapor especially to the eyes, and toxic if ingested</em>.
4. 6 M HCl: This is a concentrated strong acid, so it is <em>corrosive, has irritating vapors, flammable and toxic when ingested</em>.
5. 6 M H₂SO₄: This is also a concentrated strong acid. Moreover, it is a strong oxidizing agent. So, its hazards include: <span><em>corrosive, has irritating vapors, toxic when ingested and causes staining on skin</em>.
</span>6. 6 M HNO₃: This is a concentrated strong acid, so it is <em>corrosive, has irritating vapors, flammable and toxic when ingested</em>.
7. 7.5 M NH₃: This is a weak base. It is characterized for its pungent odor. This is <em>corrosive, has irritating vapors, toxic if ingested, and flammable</em>.
