Which of the following is the best reason to read directions carefully before beginning any type of lab?

A solution is 40.0% by volume benzene (C6H6) in carbon tetrachloride at 20C. The vapor pressure of pure benzene at this temperat

Alexandra [31]

Answer:

84.30 mm Hg

Explanation:

In 100 cm³ of solution we have: 40 cm³ C6H6 and 60 cm³ CCl4. Given the densities we can calculate their masses and number of moles, and since by Raoult´s law

Ptotal = XAPºA + XBPºB

where XA= mol fraction =na/(na +nb) and PºA vapor pressure pure of pure component A

m C6H6 = 40 cm³ x 0.87865 g/cm³ = 35.146 g

mol C6H6 = 35.146 g/ 78.11 g/mol = 0.45 mol

mass CCl4 = 60 cm³ x 1.5940 g/cm³ = 95.640 g

mol CCl4 = 95.640 g / 153.82 g/mol = 0.62 mol

mol tot = 1.07

XC6H6 = 0.45/ 1.07 = 0.42 XCCl4 = 0.62/1.07 =0.58

Ptot (mmHg) = 0.42 x 74.61 + .58 x 91.32 = 84.30 mmHg

6 0

3 years ago

Write chemically balanced equation for the following reactions

natka813 [3]

Answer:

(C)Calcium oxide reacts sulfuric acid

Explanation:

7 0

3 years ago

4. Consider the following statement made in Chapter 4 of the text: "... consider that if the

AveGali [126]

The claim: "If the nucleus were the size of a grape, the electrons would be one mile away on average" is reasonably accurate because the ratios between the nucleus's sizes and the distances (between electrons and nucleus) for the two given examples are in the same order of magnitude.

To know if the claim is accurate we need to calculate the ratio of the size of the nucleus (the same as a grape) and the distance between the electrons and the nucleus for example 1 (r₁):

$r_{1} = \frac{s_{1}}{d_{1}}$ (1)

and to compare it with the ratio of the size and the distance given in example 2 (r₂):

$r_{2} = \frac{s_{2}}{d_{2}}$ (2)

Where:

s₁: is the size of the nucleus (like the size of a grape)

d₁: is the distance between electrons and nucleus of example 1 = 1 mile

s₂: is the average diameter of the nucleus = 10⁻¹³ cm

d₂: is the average distance between electrons and nucleus of example 2 = 10⁻⁸ cm

Assuming that the diameter of a grape is 3 cm (in a spherical way), the ratio of the first example is (eq 1):

$r_{1} = \frac{3 cm}{1 mi*\frac{160934 cm}{1 mi}} = 1.86 \cdot 10^{-5}$

Now, the ratio of the second example is (eq 2):

$r_{2} = \frac{10^{-13} cm}{10^{-8} cm} = 1.00 \cdot 10^{-5}$

Since r₁ and r₂ are in the same order of magnitude (10⁻⁵), we can conclude that the given claim is reasonably accurate.

You can learn more about the nucleus of an atom here: brainly.com/question/10658589?referrer=searchResults

I hope it helps you!

3 0

3 years ago

Calling is a compound oxygen of hydrogen carbon or water

harkovskaia [24]

Explanation:

Compounds are written with formulas showing which elements from the periodic table are combined. One very familiar compound is water. When two hydrogen atoms (H2) combine with one oxygen atom (O), it makes the compound H2O, which we know as water.

7 0

3 years ago

Can anyone help me with Science Grade 6 questions , soon as possible?

jolli1 [7]

Well depending on how many people on one side of the family, you would inherite their trait more commonly.

6 0

4 years ago