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3 years ago

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True or false? To prepare 20.0 mL of 2.00 M solution of hydrochloric acid from a 10.0 M stock solution, you should take 4.00 mL

of the stock solution and add 20.0 mL of water.

1 answer:

Aleksandr-060686 [28]3 years ago

6 0

Sorry I don’t know but o have to answer for pionts

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Which is not a descriptor or tactic used by abusers?

attashe74 [19]

It should be B. All of the other choices are used often by abusers

4 0

3 years ago

Copper is formed when aluminum reacts with copper (II) sulfate in a single-replacement reaction. How many moles of copper can be

serg [7]

Answer:

The answer to your question is the limiting reactant is CuSO₄ and 0.975 moles of Cu were obtained

Explanation:

moles of Copper = ?

mass of Aluminum = 29 g

mass of CuSO₄ = 156 g

Limiting reactant = ?

Balanced Chemical reaction

3 CuSO₄ + 2 Al ⇒ 3 Cu + Al₂(SO₄)₃

Calculate the moles of reactants

CuSO₄ = 64 + 32 + (16 x 4) = 160g

Al = 27 g

160 g of CuSO₄ ----------------- 1 mol

156 g ----------------- x

x = (156 x 1) / 160

x = 0.975 moles

27 g of Al -------------------------- 1 mol

29 g of Al -------------------------- x

x = (29 x 1)/27

x = 1.07 moles

Calculate proportions to find the limiting reactant

Theoretical 3 moles CuSO₄/2 moles Al = 1.5 moles

Experimental 0.975 moles CuSO₄/1.07 moles = 0.91

The experimental proportion was lower than the theoretical proportion that means that the limiting reactant is CuSO₄.

3 moles of CuSO₄ ------------------ 3 moles of Cu

0.975 moles of CuSO₄ --------------- x

x = (0.975 x 3)/3

x = 0.975 moles of Cu were obtained.

3 0

2 years ago

Read 2 more answers

Select the pair that consists of a base and its conjugate acid in that order. CO32−/CO22−

lana [24]

Answer: The pair that consists of a base and its conjugate acid in that order. $NH_3/NH_4^+$

Explanation:

According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.

$H_3PO_4\rightarrow H_PO_4{2^-}+2H^+$

$H_2CO_3\rightarrow HCO_3^-+H^+$

$NH_3+H^+\rightarrow NH_4^+$

$HCO_3^-\rightarrow CO_3^{2-}+H^+$

$NH_3$ is gaining a proton, thus it is considered as a brønsted-lowry base and after gaining a proton, it forms $NH_4^+$ which is a conjugate acid.

3 0

2 years ago

Antarctica, almost completely covered in ice, has an area

Marysya12 [62]

<u>Answer:</u> The mass of ice is $2.39\times 10^{22}g$

<u>Explanation:</u>

We are given:

Area of Antarctica = $5,500,000mi^2=5,500,000\times 2.59\times 10^{10}=142.45\times 10^{15}cm^2$ (Conversion factor: $1mi^2=2.59\times 10^{10}cm^2$ )

Height of Antarctica with ice = 7500 ft.

Height of Antarctica without ice = 1500 ft.

Height of ice = 7500 - 1500 = 6000 ft = $182.88\times 10^3cm$ (Conversion factor: 1 ft = 30.48 cm)

To calculate mass of ice, we use the equation:

$\text{Density of a substance}=\frac{\text{Mass of a substance}}{\text{Volume of a substance}}$

We are given:

Density of ice = $0.917g/cm^3$

Volume of ice = Area × Height of ice = $142.45\times 10^{15}cm^2\times 182.88\times 10^3cm=26051.26\times 10^{18}cm^3$

Putting values in above equation, we get:

$0.917g/cm^3=\frac{\text{Mass of ice}}{26051.26\times 10^{18}cm^3}\\\\\text{Mass of ice}=(0.917g/cm^3\times 26051.26\times 10^{18}cm^3=2.39\times 10^{22}g$

Hence, the mass of ice is $2.39\times 10^{22}g$

5 0

3 years ago

How many molecules of propane were in the erlenmeyer flask? Avogadro's number is 6. 022 × 10^23 molecules/mol

Ede4ka [16]

3.74× $10^{21}$

3.74 × $10^{21}$ molecules of propane were in the erlenmeyer flask.

number of moles of propane can be calculated as moles of propane.

mass of propane = 0.274 g

molar mass of propane = 44.1

So this gives us the value of 6.21× $10^{-3}$ moles of propane

No one mole of propane As a 6.0-2 × $10^{23}$

so, 6.21 × $10^{-3}$ × 6. 022 × 10^23

= 3.74 × $10^{21}$

Therefore, molecules of propane were in the erlenmeyer flask is found to be 3.74 × $10^{21}$

<h3>What is erlenmeyer flask?</h3>

A laboratory flask with a flat bottom, a conical body, and a cylindrical neck is known as an Erlenmeyer flask, sometimes known as a conical flask or a titration flask.
It bears the name Emil Erlenmeyer after the German chemist.

<h3>What purpose does an Erlenmeyer flask serve?</h3>

Liquids are contained in Erlenmeyer flasks, which are also used for mixing, heating, chilling, incubating, filtering, storing, and other liquid-handling procedures.

For titrations and boiling liquids, their sloped sides and small necks make it possible to whirl the contents without worrying about spills.

To learn more about calculating total molecules visit:

brainly.com/question/8933381

#SPJ4

4 0

1 year ago