Answer:
Explanation:
Heat and temperature are two different but closely related concepts. Note that they have different units: temperature typically has units of degrees Celsius ( ∘ C ^\circ\text C ∘Cdegrees, start text, C, end text) or Kelvin ( Kstart text, K, end text), and heat has units of energy, Joules ( Jstart text, J, end text).
Answer:
Nitrobenzene < Bromobenzene < Benzene < Phenol
Explanation:
Aromatic compounds undergo electrophilic aromatic substitution reaction in the presence of relevant electrophiles. Certain substituents tend to increase or decrease the tendency of an aromatic compound towards electrophilic aromatic substitution reaction.
Substituents that increase the electron density around the ring such as in phenol tends to make the ring more reactive towards electrophilic substitution. Halogens such as bromine has a -I inductive effect as well as a +M mesomeric effect.
However the -I(electron withdrawing effect) of the halogens supersedes the +M electron donation due to mesomeric effect.
Putting all these together, the order of increasing reactivity of the compounds towards electrophilic aromatic substitution is;
Nitrobenzene < Bromobenzene < Benzene < Phenol
You can solve this problem through dimensional analysis.
First, find the molar mass of NaHCO3.
Na = 22.99 g
H = 1.008 g
C = 12.01 g
O (3) = 16 (3) g
Now, add them all together, you end with with the molar mass of NaHCO3.
22.99 + 1.008 + 12.01 + 16(3) = 84.008 g NaHCO3. This number means that for every mole of NaHCO3, there is 84.008 g NaHCO3. In simpler terms, 1 mole NaHCO3 = 84.008 g NaHCO3.
After finding the molar mass of sodium bicarbonate, now you can use dimensional analysis to solve for the number of moles present in 200. g of sodium bicarbonate.
![200. g NaHCO_3 * \frac{1 mole NaHCO_3}{84.008 g NaHCO_3}](https://tex.z-dn.net/?f=200.%20g%20NaHCO_3%20%2A%20%5Cfrac%7B1%20mole%20NaHCO_3%7D%7B84.008%20g%20NaHCO_3%7D)
Cross out the repeating units which are g NaHCO3, and the remaining unit is mole NaHCO3
200. * 1 = 200
200/ 84.008 = 2.38
Notice how there are only 3 sig figs in the answer. This is because the given problem only gave three sig figs.
Your final answer is 2.38 mol NaHCO3.
Answer:
The answer to your question is the second option
Explanation:
Reaction
Al₂(SO₄)₃ + KOH ⇒ Al(OH)₃ + K₂SO₄
Process
1.- Check if the reaction is already balanced
Reactants Elements Products
2 Aluminum 1
3 Sulfur 1
13 Oxygen 7
1 Potassium 2
1 Hydrogen 3
The reaction is unbalanced
2.- Balance the reaction
1Al₂(SO₄)₃ + 6KOH ⇒ 2Al(OH)₃ + 3K₂SO₄
Reactants Elements Products
2 Aluminum 2
3 Sulfur 3
18 Oxygen 18
6 Potassium 6
6 Hydrogen 6
Now the reaction is balanced. The coefficients are 1, 6, 2, 3.