A beaker of 450g of water is heated from 4.0°C to 25.0°C on a hot plate. If the

200.0 mL of 3.85 M HCl is added to 100.0 mL of 4.6 M barium hydroxide. The reaction goes to completion. What is the concentratio

Ede4ka [16]

Answer:

2.387 mol/L

Explanation:

The reaction that takes place is:

2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O

First we calculate how many moles of each reagent were added:

HCl ⇒ 200.0 mL * 3.85 M = 203.85 mmol HCl

Ba(OH)₂ ⇒ 100.0 mL * 4.6 M = 460 mmol Ba(OH)₂

460 mmol of Ba(OH)₂ would react completely with (2*460) 920 mmol of HCl. There are not as many mmoles of HCl so Ba(OH)₂ will remain in excess.

Now we calculate how many moles of Ba(OH)₂ reacted, by converting the total number of HCl moles to Ba(OH)₂ moles:

203.85 mmol HCl * $\frac{1mmolBa(OH)_{2}}{2mmolHCl}$ = 101.925 mmol Ba(OH)₂

This means the remaining Ba(OH)₂ is:

460 mmol - 101.925 mmol = 358.075 mmoles Ba(OH)₂

There are two OH⁻ moles per Ba(OH)₂ mol:

OH⁻ moles = 2 * 358.075 = 716.15 mmol OH⁻

Finally we divide the number of OH⁻ moles by the total volume (100 mL + 200 mL):

716.15 mmol OH⁻ / 300.0 mL = 2.387 M

So the answer is 2.387 mol/L

7 0

3 years ago

The number of ions in 17.1 gm of aluminum sulphate Al2 (SO4)3 =….. [Molar mass of Al2 (SO4)3 = 342 gm]

katen-ka-za [31]

Answer:

1.51 X 10^23 ions

Explanation:

The number of ions in 17.1 gm of aluminum sulphate Al2 (SO4)3 =….. [Molar mass of Al2 (SO4)3 = 342 gm]

in one molecule of Al2(SO4)3 there are 5 ions 2 aluminum and 3 sulfate ions

in 2 molecules there are 2X5= 10 ions

in 10 molecules there are 10X5 = 50 ions

molar mass of Al2(SO4)3 = (2 X 26.98) +( 3 X 32.1) + (3 X 4 X 16.0 ) =342.gms = 17.1/342 =0.0500 moles

1 mole =6.02 X 10^23 molecules ( see Avogadros number)

0.0500 moles = 0.0500 X 6.02 X 10^23 molecules =

0.301 X 10^23 molecules = 3.01 X 10^22 molecules

We determined that each molecule of Al2(SO4)3 has 5 ions

so 3.01 X10^22 molecules have 5 X 3.01 X 10^22 ions =

15.05 X 10^22 ions = 1.51 X 10^23 ions

3 0

3 years ago

How many grams of benzene (C6H6) will produce 42 grams of CO2?

3241004551 [841]

The balanced chemical reaction is:

2C6H6 + 15O2 → 12CO2 + 6H2O

We are given the amount of carbon dioxide to be produced for the reaction. This will be the starting point of our calculations.

42 g CO2 ( 1 mol CO2 / 44.01 g CO2) ( 2 mol C6H6 / 12 mol CO2 ) (78.1074 g C6H6 / 1 mol C6H6) = 12.42 grams of C6H6

7 0

3 years ago

In an electroplating process, copper (ionic charge +2e, atomic weight 63.6 g/mol) is deposited using a current of 10.0 A. What m

salantis [7]

Answer : The mass of copper deposit is, 1.98 grams

Explanation :

First we have to calculate the charge.

Formula used : $Q=I\times t$