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4 years ago

What would be the answer

Chemistry

1 answer:

ser-zykov [4K]4 years ago

4 0

Answer:

Explanation:

The balanced equation for the reaction is as follows:

4Al + 3O2 --> 2(Al2O3)

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Calculate the pressure in atmospheres exerted by 10.0 moles of hydrogen gas at 293 Kelvin if it is stored in a 7.50 liter contai

mel-nik [20]

You rearrange the ideal gas law equation to solve for the pressure by just plugging in the given values.

5 0

3 years ago

This diagram illustrates the life cycle of a tomato plant. Which stage in this plant life cycle is the adult? Tomato Plant Life

GuDViN [60]

Answer:

the answer is A

Explanation:

hope it hlp

7 0

3 years ago

Tris is a weak base. The basic form of tris can be written tris0 and the protonated (conjugate acid) form can be written tris. T

Arada [10]

Answer:

a) [Tris0] : [Tris] = 1 : 100

b) Range = 7.1 to 9.1

Explanation:

a) Calculation of ratio of the basic and the acidic forms of tris

pH of a buffer is calculate using Henderson-Hasselbalch equation

$pH = pKa+log\frac{Salt}{Acid}$

Conjugate acid of Tris dissociated as

$Tris \leftrightharpoons Tris0 + H^+$

For tris,

Salt or Basic form = tris0

Acid or Acidic form = Tris

pKa = 8.1

pH = 6.1

$pH = pKa+log\frac{Tris0}{Tris}$

$6.1 = 8.1+log\frac{Tris0}{Tris}$

$log\frac{Tris0}{Tris} = -2$

$\frac{Tris0}{Tris} = antilog (-2)$

$\frac{Tris0}{Tris} = 10^{-2}$

[Tris0] : [Tris] = 1 : 100

b) Range of Tris

Range of any buffer is:

From (pKa -1) to (pKa+1)

So, range of Tris is:

From (8.1 - 1) to (8.1 +1)

or from 7.1 to 9.1

8 0

3 years ago

The freezing point of ethanol, CH3CH2OH, is -117.300 °C at 1 atmosphere. Kf(ethanol) = 1.99 °C/m

MAXImum [283]

Answer : The molecular weight of this compound is 891.10 g/mol

Explanation : Given,

Mass of compound = 12.70 g

Mass of ethanol = 216.5 g

Formula used :

$\Delta T_f=i\times K_f\times m\\\\T_f^o-T_f=i\times T_f\times\frac{\text{Mass of compound}\times 1000}{\text{Molar mass of compound}\times \text{Mass of ethanol}}$

where,

$\Delta T_f$ = change in freezing point

$T_f^o$ = temperature of pure ethanol = $-117.300^oC$

$T_f$ = temperature of solution = $-117.431^oC$

$K_f$ = freezing point constant of ethanol = $1.99^oC/m$

i = van't hoff factor = 1 (for non-electrolyte)

m = molality

Now put all the given values in this formula, we get

$(-117.300)-(-117.431)=1\times 1.99^oC/m\times \frac{12.70g\times 1000}{\text{Molar mass of compound}\times 216.5g}$

$\text{Molar mass of compound}=891.10g/mol$

Therefore, the molecular weight of this compound is 891.10 g/mol

7 0

3 years ago

A map here shows the motion of a tectonic plate off the coast of the western united states. Which evidence supports the theory o

notsponge [240]

Answer:

Fossils, the shape of continents, the mid-ocean ridge system, sea floor sediment deposits, and the magnetism of rocks.

Explanation:

Fossils, the continent's shape, the mid-ocean ridge system, sea floor sediment deposits, and the magnetism of rocks on the sea floor are the evidences that support the theory of plate tectonics in the area. Fossils provides information to us when and where plants and animals once existed. Due to diverging plates, some life became isolated, and evolved into new species. Continental ‘fit’ through coastline matching. Some division of continents look as though they should fit together, e.g. South America and Africa.

7 0

3 years ago