Convert a pressure of 0.0248 mm Hg to the equivalent pressure in pascals (Pa). How did you get your answer ?

We would like to make a golden standard kilogram in the shape of circular cylinder. The density of gold is 19.32 g/cm3. a) Find

iragen [17]

Explanation:

a) Using the provided information about the density of gold, the sample size, thickness, and the following equations and comersion factors, find the area of the gold leaf:

$V=l \cdot w \cdot h=A \cdot h\\m=\rho \cdot V$

Gold $_{\rho}=19.32 \mathrm{g} / \mathrm{cm}^{3}$

$1 \mu=10^{-6} \mathrm{m}$

First, find the volume of the sample and then find the area of the sample.

$V=\frac{m}{\rho}=\frac{27.6 \mathrm{g}}{19.32 \mathrm{g} / \mathrm{cm}^{3}} \cdot\left(\frac{0.01 \mathrm{m}}{1 \mathrm{cm}}\right)^{3}$ $=\frac{1.429 \times 10^{-6} \mathrm{m}^{3}}$

$V=A \cdot h \rightarrow A=\frac{V}{h}=\frac{1.429 \times 10^{-6} \mathrm{m}^{3}}{10^{-6} \mathrm{m}} \approx 1.429 \mathrm{m}^{2}$

b. Using the provided information from part $a$ ), the radius of the cylinder, and the following equation for the volume of a cylinder, find the length of the fiber :

$V=\pi r^{2} h \rightarrow h=\frac{V}{\pi r^{2}}$

$h=\frac{1.429 \times 10^{-6} \mathrm{m}^{3}}{\pi \cdot\left(2.5 \times 10^{-6} \mathrm{m}\right)^{2}} \approx 72778 \mathrm{m}$

8 0

2 years ago

A 2.80 g sample of Al reacts with 4.15 g sample of Cl2 according to the equation shown below.

solong [7]

Answer:

Mass = 5.33 g

Explanation:

Given data:

Mass of Al = 2.80 g

Mass of Cl₂ = 4.15 g

Theoretical yield of AlCl₃ = ?

Solution:

Chemical equation:

2Al + 3Cl₂ → 2AlCl₃

Number of moles of Al:

Number of moles = mass/molar mass

Number of moles = 2.80 g/ 27 g/mol

Number of moles = 0.10 mol

Number of moles of Cl₂:

Number of moles = mass/molar mass

Number of moles = 4.15 g/71 g/mol

Number of moles = 0.06 mol

Now we will compare the moles of AlCl₃ with Al and Cl₂.

Cl₂ : AlCl₃

3 : 2

0.06 : 2/3×0.06 = 0.04

Al : AlCl₃

2 : 2

0.10 : 0.10

Number of moles of AlCl₃ produced by chlorine are less so it will be limiting reactant.

Mass of AlCl₃:Theoretical yield

Mass = number of moles ×molar mass

Mass = 0.04 mol × 133.34 g/mol

Mass = 5.33 g

4 0

1 year ago

What is the ph of a solution of 0.400 m k2hpo4, potassium hydrogen phosphate?

dusya [7]

When we can get Pka for K2HPO4 =6.86 so we can determine the Ka :

when Pka = - ㏒ Ka

6.86 = -㏒ Ka

∴Ka = 1.38 x 10^-7

by using ICE table:

H2PO4- → H+ + HPO4
initial 0.4 m 0 0

change -X +X +X

Equ (0.4-X) X X

when Ka = [H+][HPO4] / [H2PO4-]

by substitution:

1.38 X 10^-7 = X^2 / (0.4-X) by solving for X

∴X = 2.3x 10^-4

∴[H+] = X = 2.3 x 10^-4

∴PH = -㏒[H+]

= -㏒ (2.3 x 10^-4)
∴PH = 3.6

3 0

1 year ago

What volume of 0.500 M HNO₃(aq) must completely react to neutralize 100.0 milliliters of 0.100 M KOH(aq)?

USPshnik [31]

Answer:

v = 500 milliliters

Explanation:

$HNO_{3}$ ⇒ $H^{+} + NO^{3-}$

$KOH$ ⇒ $K^{+} + OH^{-}$

1 $H^{+}$ to 1 $OH^{-}$

$\frac{0,5}{V} = \frac{0,1}{100} \\\\v * 0,1 = 50\\v = 500 milliliters$

4 0

1 year ago

aleksA sailor on a trans-Pacific solo voyage notices one day that if he puts of fresh water into a plastic cup weighing , the cu

finlep [7]

Answer:

40 g

See explaination

Explanation:

Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.

Check attachment for the detailed step by step solution of the given problem.

3 0

1 year ago