In which of these situations would light slow down?

100.0 mL of Ca(OH)2 solution is titrated with 5.00 x 10–2 M HBr. It requires 36.5 mL of the acid solution for neutralization. Wh

miskamm [114]

Answer:

The number of moles HBr = 0.001825

The concentration of Ca(OH)2 = 0.009125 M

Explanation:

Step 1: Data given

Volume of the Ca(OH)2 = 100.0 mL = 0.100 L

Molarity of HBr = 5.00 * 10^-2 M

Volume of HBR = 36.5 mL = 0.0365 L

Step 2: The balanced equation

Ca(OH)2 + 2HBr → CaBr2 + 2H2O

Step 3: Calculate molarity of Ca(OH) 2

b*Va* Ca = a * Vb*Cb

⇒with b = the coefficient of HBr = 2

⇒with Va = the volume of Ca(OH)2 = 0.100 L

⇒with ca = the concentration of Ca(OH)2 = TO BE DETERMINED

⇒with a = the coefficient of Ca(OH)2 = 1

⇒with Vb = the volume of HBr = 0.0365 L

⇒with Cb = the concentration of HBr = 5.00 * 10^-2 = 0.05 M

2 * 0.100 * Ca = 1 * 0.0365 * 0.05

Ca = (0.0365*0.05) / 0.200

Ca = 0.009125 M

Step 4: Calculate moles HBr

Moles HBr = concentration HBr * volume HBr

Moles HBr = 0.05 M * 0.0365 L

Moles HBr = 0.001825 moles

3 0

3 years ago

0.0145 moles of helium gas are introduced into a balloon so that the volume of the balloon is 2.54 liters. An additional amount

olga_2 [115]

Answer:

4.43L is final volume of the ballon

Explanation:

Avogadro's law of ideal gases states that equal volumes of gases, at the same temperature and pressure, have the same number of molecules.

The formula is:

$\frac{V_1}{n_1} =\frac{V_2}{n_2}$

Where V and n are volume and moles of the gas in initial and final conditions.

If the initial conditions are 0.0145 moles and 2.54L and final amount of moles is 0.0253moles, final volume is:

$\frac{2.54L}{0.0145mol} =\frac{V_2}{0.0253mol}$

V₂ = 4.43L is final volume of the ballon

6 0

3 years ago

If the lab technician needs 30 liters of a 25% acid solution, how many liters of the 10% and the 30% acid solutions should she m

Mice21 [21]

Answer:

7.5 L of the 10% and 22.5 L of the 30% acid solution, she should mix.

Explanation:

Let the volume of 10% acid solution used to make the mixture = x L

So, the volume of 30% acid solution used to make the mixture = y L

Total volume of the mixture = x + y = 30 L .................. (1)

For 10% acid solution:

C₁ = 10% , V₁ = x L

For 30% acid solution :

C₂ = 30% , V₂ = y L

For the resultant solution of sulfuric acid:

C₃ = 25% , V₃ = 30 L

Using

C₁V₁ + C₂V₂ = C₃V₃

10×x + 30×y = 25×30

So,

x + 3y = 75 .................. (2)

Solving 1 and 2 we get,

x = 7.5 L

y = 22.5 L

6 0

3 years ago

125.0 g of an unknown substance is heated to 97.0°C. It is then placed in a calorimeter than contains 250g of water with an init

Sveta_85 [38]

The heat released by the substance in the calorimeter is equal to the heat absorbed by water which results to the decrease and increase in temperature, respectively.
We use m Cp ΔT to balance the heat involved

(m Cp ΔT) subs in calorimeter = (m Cp ΔT) water
125 g * Cp * (97.0-23.5 ) C = 250 g *(4.18 J/C g)* (23.5-20)
Cp = 0.398 J/Cg

Answer is B

4 0

3 years ago

Read 2 more answers

How is the scientific definition of "heat" different from how we use it every day? PLEASE NEED THE ANSWER ASAP

klio [65]

Heat is energy, that can be transferred to another item, which is “less hot”.

3 0

3 years ago