Which sentence best describes how scientists plan out their experiments?

Why do we use a double arrow in the dissociation equation for a weak acid answer?

Zepler [3.9K]

Answer is: because weak acids do not dissociate completely.

The strength of an Arrhenius acid determines percentage of ionization of acid and the number of H⁺ ions formed. <span>
Strong acids completely ionize in water and give large amount ofhydrogen ions (H</span>⁺), so we use only one arrow, because reaction goes in one direction and there no molecules of acid in solution.

For example hydrochloric acid: HCl(aq) → H⁺(aq) + Cl⁻(aq).

<span> Weak acid partially ionize in water and give only a few hydrogen ions (H</span>⁺), in the solution there molecules of acid and ions.

For example cyanide acid: HCN(aq) ⇄ H⁺(aq) + CN⁻(aq).

4 0

2 years ago

Liquid hexane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 6.9 g of hexane is mi

MrRa [10]

Answer:

There, there are no leftover for C6H14 instead, an additional mass of 4g of C6H14 is needed to completely react with 38.4g of O2.

Explanation:

Step 1:

We'll begin by writing the balanced equation for the reaction. This is shown below:

2C6H14 + 19O2 —> 12CO2 + 14H2O

Step 2:

Let us calculate the masses of C6H14 and O2 that reacted from the balanced equation. This is illustrated below:

2C6H14 + 19O2 —> 12CO2 + 14H2O

Molar Mass of C6H14 = (12x6) + (14x1) = 72 + 14 = 86g/mol

Mass of C6H14 from the balanced equation = 2 x 86 = 172g

Molar Mass of O2 = 16x2 =32g/mol

Mass of O2 from the balanced equation = 19 x 32 = 608g

From the balanced equation above, 172g of C6H14 reacted with 608g of O2.

Step 3.

Now, let us determine the mass of C6H14 that will react with 38.4 g of oxygen. This is illustrated below:

From the balanced equation above, 172g of C6H14 reacted with 608g of O2.

Therefore, Xg of C6H14 will react with 38.4g of O2 i.e

Xg of C6H14 = (172 x 38.4) /608

Xg of C6H14 = 10.9g

From the calculations made above, we can see clearly that the mass of C6H14 is limited as the reaction requires 10.9g of C6H14 and only 6.9g was given. There, there are no leftover for C6H14 instead, an additional mass ( 10.9 - 6.9 = 4g) of 4g of C6H14 is needed to completely react with 38.4g of O2.

5 0

2 years ago

A 1.42-g sample of a pure compound with formula m2so4 was dissolved in water and treated with an ex- cess of aqueous calcium chl

solong [7]

The reaction between $m_{2}SO_{4}$ with calcium chloride can be shown as- $m_{2}SO_{4}$ + $CaCl_{2}$ → $CaSO_{4}$ ↓+2mCl. The molecular weight of $CaSO_{4}$ is 136.14g. The weight of sulfate ion is 96.06g. The molecular weight of $m_{2}SO_{4}$ = (2×m + 96.06). From the reaction we can see that 1 mole of calcium chloride reacts with 1 moles $m_{2}SO_{4}$ to produce 1 mole of calcium sulfate. Now 1.36g of calcium sulfate is equivalent to 1.36/136.14=9.989× $10^{-3}$ moles of calcium sulfate.

Thus, 9.989× $10^{-3}$ moles of $m_{2}SO_{4}$ reacts in this reaction.

Let assume the atomic mass of m is x thus the molecular weight of $m_{2}SO_{4}$ is 2x+96.

So we may write 9.989× $10^{-3}$ × (2x+96) =1.42

Or, 2x + 96 = 142.146

Or, 2x = 46.146

Or, x = 23.073

Thus the atomic mass of m is 23.073. The atom (m) is sodium (Na).

8 0

3 years ago

describe some acidic oxides that can be prepared by the thermal decomposition of nitrates and carbonates

ale4655 [162]

The oxidation is the best thing

7 0

2 years ago

When you take 10 grams of salt, and dissolve it in 25 grams of hot water what is the solubility

AURORKA [14]

Answer:

When salt is mixed with water, the salt dissolves because the covalent bonds of water are stronger than the ionic bonds in the salt molecules. ... Water molecules pull the sodium and chloride ions apart, breaking the ionic bond that held them together.

Explanation:

4 0

2 years ago