Magnesium. You can count the electrons in each level and because the number of electrons is the same with protons you have the atomic number based of which you can get the element in the periodic table

3 0

2 years ago

Amphetamine (C9H13N)(C9H13N) is a weak base with a pKbpKb of 4.2. You may want to reference (Pages 710 - 713) Section 16.8 while

Soloha48 [4]

Answer:

pH = 10.38

Explanation:

C9H13N ↔ C9H20O3N+ + OH-

∴ molar mass C9H13N = 135.21 g/mol

∴ pKb = - log Kb = 4.2

⇒ Kb = 6.309 E-5 = [OH-][C9H20O3N+] / [C9H13N]

∴ C sln = (205 mg/L )*(g/1000 mg)*(mol/135.21 g) = 1.516 E-3 M

mass balance:

⇒ C sln = 1.516 E-3 = [C9H20O3N+] + [C9H13N]......(1)

charge balance:

⇒ [C9H20O3N+] + [H3O+] = [OH-]; [H3O+] is neglected, come from water

⇒ [C9H20O3N+] = [OH-].......(2)

(2) in (1):

⇒ [C9H13N] = 1.516 E-3 - [OH-]

replacing in Kb:

⇒ Kb = 6.3096 E-5 = [OH-]² / (1.516 E-3 - [OH-])

⇒ [OH-]² + 6.3096 E-5[OH] - 7.26613 E-8 = 0

⇒ [OH-] = 2.3985 E-4 M

∴ pOH = - Log [OH-]

⇒ pOH = 3.62

⇒ pH = 14 - pOH = 14 - 3.62 = 10.38

5 0

2 years ago

In carbon monoxide, CO, the mass ratio is 1.00 g of carbon for every 1.33 g of oxygen. How many grams of oxygen will be combined

notsponge [240]

Answer : The mass of oxygen combined with 1.00 g of carbon in carbon dioxide will be, 2.66 grams.

Explanation :

Law of multiple proportion : It states that when two elements can combine to form two or more different compounds then the mass of one element compared to fixed mass of the other will always be in a ratio of small whole numbers.

As we are given that the mass of ratio of carbon and oxygen in CO is 1 gram and 1.33 gram.

Ratio of C and O in CO = 1 : 1

Ratio of C and O in CO₂ = 1 : 2

So, the mass of ratio of carbon and oxygen in CO₂ will be 1 gram and (2×1.33) 2.66 gram.

Thus, the mass of oxygen combined with 1.00 g of carbon in carbon dioxide will be, 2.66 grams.

8 0

2 years ago

Methanol can be produced by the following reaction: CO(g) 2 H2(g) CH3OH(g). How is the rate of disappearance of hydrogen gas rel

belka [17]

Answer:

$r_{H_2}=-2r_{CH_3OH}$

Explanation:

Hello!

In this case, for the reaction:

$CO(g)+ 2 H_2(g) \rightarrow CH_3OH(g)$

In such a way, via the rate proportions, that is written considering the stoichiometric coefficients, we obtain:

$\frac{1}{-1} r_{CO}=\frac{1}{-2} r_{H_2}=\frac{1}{1} r_{CH_3OH}$

Whereas the reactants, CO and H2 have negative stoichiometric coefficients; therefore the rate of disappearance of hydrogen gas is related to the rate of appearance of methanol as shown below:

$\frac{1}{-2} r_{H_2}=\frac{1}{1} r_{CH_3OH}\\\\r_{H_2}=\frac{-2}{1} r_{CH_3OH}\\\\r_{H_2}=-2r_{CH_3OH}$

Which means that the rate of disappearance of hydrogen gas is negative and the rate of appearance of methanol is positive.

Regards!

7 0

2 years ago