Answer:
The Bohr model of the atom explains the reactivity of all atoms.
Answer:
26 grams of D will be produced.
Explanation:
The reaction is given by:
A + B -----> C + D
Mass of A reacted = 21 g
Mass of B reacted = 22 g
Mass of C formed = 17 g
Mass of D formed = m =?
According to law of conservation of mass, the total mass of the reactants used is equal to the total mass of the product formed.
Then:
mass of A reacted + mass of B reacted = mass of C formed + mass of D formed
21 + 22 = 17 + m
m = 26 g
Solution: Sentence D is a scientific statement.
Scientific statement is a statement that defines the science behind any situation. There should be any experimental result or observation to state any scientific statement. Also, the statement should be accepted by considering other scientific aspects.
Here, statement A can not be a scientific statement as different aromas of cooked food are liked by different people. Any one can find aroma of cooked food in copper better than the ceramic pot.
Thus, the statement can be proved wrong easily.
Statement B can not be a scientific statement as people can find the taste of normal water (without ice cubes) better than the ice cold water.
Statement C is not a scientific statement as there is no science behind watching baseball or ice hockey, it depends on the liking of today's people.
Statement D is a scientific statement because this can be scientifically proved.
Answer:
pH = 5.54
Explanation:
The pH of a buffer solution is given by the <em>Henderson-Hasselbach (H-H) equation</em>:
- pH = pKa + log
![\frac{[CH_3COO^-]}{[CH_3COOH]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BCH_3COO%5E-%5D%7D%7B%5BCH_3COOH%5D%7D)
For acetic acid, pKa = 4.75.
We <u>calculate the original number of moles for acetic acid and acetate</u>, using the <em>given concentrations and volume</em>:
- CH₃COO⁻ ⇒ 0.377 M * 0.250 L = 0.0942 mol CH₃COO⁻
- CH₃COOH ⇒ 0.345 M * 0.250 L = 0.0862 mol CH₃COOH
The number of CH₃COO⁻ moles will increase with the added moles of KOH while the number of CH₃COOH moles will decrease by the same amount.
Now we use the H-H equation to <u>calculate the new pH</u>, by using the <em>new concentrations</em>:
- pH = 4.75 + log
= 5.54