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3 years ago

At a room temperature, which of the following will evaporate first, a drop of water or a drop of ethanol

Chemistry

2 answers:

Angelina_Jolie [31]3 years ago

5 0

Ethanol will evaporate first because it is more volatile or has a lower boiling point than water.

elena-14-01-66 [18.8K]3 years ago

3 0

Answer:

The water and the alcohol will start to evaporate once you start blowing on your hand. Compared with water, alcohol has a lower heat of evaporation. That means that for the same amount of liquid, more heat transfer occurs during the evaporation of water compared with the alcohol.

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CS2 (s) + 3 O2 (g) → CO2 (g) + 2 SO2 (g)

Natasha_Volkova [10]

Answer:

2.067 L ≅ 2.07 L.

Explanation:

The balanced equation for the mentioned reaction is:

CS₂(g) + 3O₂(g) → CO₂(g) + 2SO₂(g),

It is clear that 1.0 mole of CS₂ react with 3.0 mole of O₂ to produce 1.0 mole of CO₂ and 2.0 moles of SO₂.

At STP, 3.6 L of H₂ reacts with (?? L) of oxygen gas:

It is known that at STP: every 1.0 mol of any gas occupies 22.4 L.

using cross multiplication:

1.0 mol of O₂ represents → 22.4 L.

??? mol of O₂ represents → 3.1 L.

∴ 3.1 L of O₂ represents = (1.0 mol)(3.1 L)/(22.4 L) = 0.1384 mol.

To find the no. of moles of SO₂ produced from 3.1 liters (0.1384 mol) of hydrogen:

Using cross multiplication:

3.0 mol of O₂ produce → 2.0 mol of SO₂, from stichiometry.

0.1384 mol of O₂ produce → ??? mol of SO₂.

∴ The no. of moles of SO₂ = (2.0 mol)(0.1384 mol)/(3.0 mol) = 0.09227 mol.

Again, using cross multiplication:

1.0 mol of SO₂ represents → 22.4 L, at STP.

0.09227 mol of SO₂ represents → ??? L.

∴ The no. of liters of SO₂ will be produced = (0.09227 mol)(22.4 L)/(1.0 mol) = 2.067 L ≅ 2.07 L.

8 0

3 years ago

HELPPP

Ksivusya [100]

3 I’m pretty sure maybe

4 0

2 years ago

Identify the term that applies to each definition.

Illusion [34]

Answer:

A. Reference blank

B. Cuvettes

C. Transmittance

D. Absorbance

E. Wavelength

Explanation:

A reference blank is a sample prepared using the solvent and any other chemicals in the sample solutions, but not the absorbing substance.

A square-shaped container, typically made of quartz, designed to hold samples in a spectrophotometer is known as Cuvettes.

A measurement of the amount of light that passes through a sample or percentage of light transmitted by the sample, with the respective intensities of the incident and transmitted beams is called Transmittance.

The measurement of the amount of light taken in by a sample is known as Absorbance

The wavelength is also the distance travelled by the wave during a period of oscillation. In spectrophotometry, the unit is inversely proportional to energy and commonly measured in nanometers

6 0

3 years ago

A 3.4 g sample of an unknown monoprotic organic acid composed of C,H, and O is burned in air to produce 8.58 grams of carbon dio

Pavlova-9 [17]

Answer:

$C_7H_6O_2$

Explanation:

Hello there!

In this case, we can divide the problem in three stages: (1) determine the empirical formula with the combustion analysis, (2) compute the molar mass of acid via the moles of the acid in the neutralization and (3) determine the molecular formula.

(1) In this case, since 8.58 g of carbon dioxide are released, we can first compute the moles of carbon in the compound:

$n_C=8.58gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molC}{1molCO_2}=0.195molC$

And the moles of hydrogen due to the produced 1.50 grams of water:

$n_H=1.50gH_2O*\frac{1molH_2O}{18.02gH_2O}*\frac{2molH}{1molH_2O} =0.166molH$

Next, to compute the mass and moles of oxygen, we need to use the initial 3.4 g of the acid:

$m_O=3.4g-0.195molC*\frac{12.01gC}{1molC}-0.166molH*\frac{1.01gH}{1molH} =0.89gO\\\\n_O=0.89gO*\frac{1molO}{16.0gO}=0.0556molO$

Thus, the subscripts in the empirical formula are:

$C=\frac{0.195}{0.0556}=3.5 \\\\H=\frac{0.166}{0.0556}=3\\\\O=\frac{0.0556}{0.0556}=1\\\\C_7H_6O_2$

As they cannot be fractions.

(2) In this case, since the acid is monoprotic, we can compute the moles by multiplying the concentration and volume of KOH:

$n_{KOH}=0.279L*0.1mol/L\\\\n_{KOH}=0.0279mol$

Which are equal to the moles of the acid:

$n_{acid}=0.0279mol$

And the molar mass:

$MM_{acid}=\frac{3.4g}{0.0279mol} =121.86g/mol$

(3) Finally, since the molar mass of the empirical formula is:

7*12.01 + 6*1.01 + 2*16.00 = 122.13 g/mol

Thus, since the ratio of molar masses is 122.86/122.13 = 1, we infer that the empirical formula equals the molecular one:

$C_7H_6O_2$

Best regards!

8 0

3 years ago

As you move from left to right across the periodic table elements ?

Sidana [21]

Explanation:

Quite a number of properties varies across a period. Some remains constant whereas others decreases.

As one moves from left to right;

The energy level remains the same.
The ionization energy increases progressively as a result of increasing nuclear charge.
Electron affinity increases from left to right.
Electronegativity increases.
Electropositivity decreases.

learn more:

Periodic table brainly.com/question/2014634

#learnwithBrainly

6 0

3 years ago