Answer:
False.
Explanation:
Snow forms when tiny ice crystals in clouds stick together to make snowflakes.
The answer is 3/4.
The coefficient next to each reactant represents the amount of moles. The compound for oxygen is O2 and the compound for aluminum is 4. We can see that the number next to O2 is 3 and the number next to aluminum is 4.
Answer:
- <em>To balance a chemical equation it may be necessary to adjust the </em><u>coefficients.</u>
Explanation:
The <em>coefficients</em> of a <em>chemical equation</em> are the numbers that you put in front of each reactant and product. They are used to balance the equation and comply with the law of mass conservation.
By adjusting the coefficients you obtain the relative amounts (moles) of each product and reactant, i.e. the mole ratios.
Here an example.
The first information is what is called a word equation. E.g. nitrogen and hydrogen react to form ammonia:
- Word equation: hydrogen + nitrogen → ammonia
- Skeleton equation: H₂ + N₂ → NH₃
This equation shows the chemical formulae but it is not balanced. The law of mass conservation is not observed.
So, in order to comply with the law of mass conservation you adjust the coefficients as follow.
- Balanced chemical equation: 3H₂ + N₂ → 2NH₃
As you see, it was necessary to modify the coefficients. Now the law of conservation of mass is observed and you get the mole ratios:
- 3 mol H₂ : 1 mol N₂ : 2 mol NH₃
Answer:
The final and initial concentration of the acid and it's conjugate base are approximately equal, that is we use the weak acid approximation.
Explanation:
The Henderson-Hasselbalch is used to calculate the pH of a buffer solution. It depends on the weak acid approximation.
Since the weak acid ionizes only to a small extent, then we can say that [HA] ≈ [HA]i
Where [HA] = final concentration of the acid and [HA]i = initial concentration of the acid.
It also follows that [A^-] ≈ [A^-]i where [A^-] and[A^-]i refer to final and initial concentrations of the conjugate base hence the answer above.
