All categories

3 years ago

Be sure to answer all parts.

Chemistry

1 answer:

tangare [24]3 years ago

7 0

Answer:

(a) cesium bromide (CsBr): 9.15 grams

(b) calcium sulfate (CaSO4): 5.85 grams

(d) lithium dichromate (Li2Cr2O7): 9.88 grams

(e) potassium oxalate (K2C2O4): 7.15 grams

Explanation:

(a) cesium bromide (CsBr):

Molar mass of CsBR = 212.81 g/mol

Number of moles = molarity * volume

Number of moles = 0.100 M *0.43 L

Number of moles = 0.043 moles

Mass of CsBr required = moles * Molar mass

Mass of CsBr required = 0.043 moles * 212.81 g/mol

Mass of CsBr required = 9.15 grams

(b) calcium sulfate (CaSO4):

Molar mass of CaSO4 = 136.14 g/mol

Mass of CaSO4 required = moles * Molar mass

Mass of CaSO4 required = 0.043 moles * 136.14 g/mol

Mass of CaSO4 required = 5.85 grams

(c) sodium phosphate (Na3PO4):

Molar mass of Na3PO4 = 163.94 g/mol

Mass of Na3PO4 required = moles * Molar mass

Mass of Na3PO4 required = 0.043 moles * 163.94 g/mol

Mass of Na3PO4 required = 7.05 grams

(d) lithium dichromate (Li2Cr2O7):

Molar mass of Li2Cr2O7 = 229.87 g/mol

Mass of Li2Cr2O7 required = moles * Molar mass

Mass of Li2Cr2O7 required = 0.043 moles * 229.87 g/mol

Mass of Li2Cr2O7 required = 9.88 grams

(e) potassium oxalate (K2C2O4):

Molar mass of K2C2O4 = 166.22 g/mol

Mass of K2C2O4 required = moles * Molar mass

Mass of K2C2O4 required = 0.043 moles * 166.22 g/mol

Mass of K2C2O4 required = 7.15 grams

You might be interested in

Consider this initial-rate data at a certain temperature for the reaction described by N2O3(

Yuliya22 [10]

N2O3(g)→NO(g)+NO2(g)

[N2O3] Initial Rate
0.1 M r(t)=0.66 M/s
0.2 M r(t)=1.32 M/s
0.3 M r(t)=1.98 M/s

We can have the relationship:

([N2O3]/[N2O3]0)^m=r(t)/r0(t)
However,
([N2O3]/[N2O3]0) = 2

Also, we assume m=1 which is the order of the reaction.

Thus, the relationship is simplified to,

r(t)/r0(t) = 2

r(t)=k[N2O3]

0.66 M/s=k×0.1 M

k=6.6 s−1

6 0

3 years ago

Read 2 more answers

A gas has a pressure of 5.7 atm at 100.0°C. What is its pressure at20.0°C (Assume volume is unchanged)

son4ous [18]

Answer:

$\large \boxed{\text{4.5 atm}}$

Explanation:

The volume and amount of gas are constant, so we can use Gay-Lussac’s Law:

At constant volume, the pressure exerted by a gas is directly proportional to its temperature.

$\dfrac{p_{1}}{T_{1}} = \dfrac{p_{2}}{T_{2}}$

Data:

p₁ =5.7 atm; T₁ = 100.0 °C

p₂ = ?; T₂ = 20.0 °C

Calculations:

1. Convert the temperatures to kelvins

T₁ = (100.0 + 273.15) K = 373.15

T₂ = (20.0 + 273.15) K = 293.15

2. Calculate the new pressure

$\begin{array}{rcl}\dfrac{5.7}{373.15} & = & \dfrac{p_{2}}{293.15}\\\\0.0153 & = & \dfrac{p_{2}}{293.15}\\\\0.0153\times 293.15 &=&p_{2}\\p_{2} & = & \textbf{4.5 atm}\end{array}\\\text{The new pressure will be $\large \boxed{\textbf{4.5 atm}}$}$

6 0

3 years ago

25.0 mL of a hydrofluoric acid solution of unknown concentration is titrated with 0.200 M NaOH. After 20.0 mL of the base soluti

lesantik [10]

Answer:

[HF]₀ = 0.125M

Explanation:

NaOH + HF => NaF + H₂O

Adding 20ml of 0.200M NaOH into 25ml of HF solution neutralizes 0.004 mole of HF leaving 0.004 mole NaF in 0.045L with 0.001M H⁺ at pH = 3. This is 0.089M NaF and 0.001M HF remaining.

=> 45ml of solution with pH = 3 and contains 0.089M NaF from titration becomes a common ion problem.

HF ⇄ H⁺ + F⁻

C(eq) [HF] 10⁻³M 0.089M (<= soln after adding 20ml 0.200M NaOH)

Ka = [H⁺][F⁻]/[HF]₀ => [HF]₀ = [H⁺][F⁻]/Ka

[HF]₀ = (0.001)(0.089)/(7.1 x 10⁻⁴) M = 0.125M

6 0

3 years ago

Which of the following are weak electrolytes in water

anzhelika [568]

Not strong base and acid, not dissolved or not aqueous.

4 0

3 years ago

Read 2 more answers

Use complete sentences to differentiate between acids and bases on the basis of their behavior when dissolved in water. Give an

forsale [732]

Bases and Acids are chemically opposite from each other,and there are multiple ways to distinguish how they react when dissolved in water. One accepted definition is that an acid is any chemical substance that, when it is dissolved in water, creates a solution with hydrogen ion activity greater than pure/neutral water. That is, it donates a proton to the solution. Any substance with a pH less than 7.0 is an acid, and includes substances such as vinegar and lemon juice. By comparison, a base is any chemical substance that, when it is dissolved in water, creates a solution in which has hydrogen ion activity less than pure/neutral water. That is, it accepts protons. Any substance with a pH greater than 7.0 is a base, and includes substances such as ammonia and baking soda.

4 0

3 years ago

Read 2 more answers