Answer:
Chemical indicator, any substance that gives a visible sign, usually by a color change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow color to an alkaline solution.
Answer:
D. 40 % increase
Step-by-step explanation:
r = k[A]²/[B]
The rate is inversely proportional to [B]. If [B] is doubled, the rate is halved.
We must double this rate to get back to the original.
The rate is directly proportional to [A]².
2 = [A]₂/[A]₁² Take the square root of each side
√2 = [A]₂/[A]₁ Multiply each side by [A]₁
[A]₂ = √2[A]₁
[A]₂ = 1.41[A]₁
We must increase [A] by 41 %.
Answer:
The correct answer is - 3.012×10^23 molecules
Explanation:
The number of molecules is present in any mole of an element or compound are the same. To find the molecules you need to multiply the number of the moles of the compound by Avogadro's number:
Moles are calculated from the molecular weight, for AlF3
= 26.98 + 3×19
= 26.98 + 57
= 83.98
Then moles in 42 grams:
= 42/83.98
= 0.5001190 moles
Now the number of molecules = moles*Avogadro's number
= 0.500110×6.022×10^23
= 3.011×10^23 molecules
The correct answer is A, since it is the only sensible answer.
Answer:
True
Explanation: Imagine the Electrons is by the nucleus which give more energy.
