All categories

12 days ago

If 20.0g of MgSO4⋅7H2O is thoroughly heated, what mass of anhydrous magnesium sulfate will remain?

2 answers:

7 0

We know that:
<span>MgSO4.7H2O + heat = MgSO4 + 7 H2O
</span>Along with the following:
Molar mass of MgSO₄⋅7H₂O = 246.47 g/mole
Molar mass of anhydrous MgSO₄ = 120.415 g/mole

Consequently,
<span>Mass of anhydrous magnesium sulfate left over = (20 grams of MgSO₄⋅7H₂O) / (246.4746 g/mol of MgSO₄⋅7H₂O) x (1 mole of MgSO₄ / 1 mole of MgSO₄⋅7H₂O) x (120.3676 g/mol of MgSO₄)
= 7.7 grams of MgSO4</span>

KiRa [971]12 days ago

5 0

Answer: 9.8g

Explanation:

This calculation assumes complete removal of water from the compound.

From there, I will determine the mass of the evaporated water and subtract that from the initial 20.0 g sample.

To do this, follow these steps:

1) Calculate the number of moles of hydrated magnesium sulfate, represented as MgSO₄⋅7H₂O

Number of moles = mass in grams / molar mass

The molar mass of MgSO₄⋅7H₂O can be calculated using the atomic masses of its constituent atoms multiplied by the number of each atom present:

Molar mass = 24.305 g/mol + 32.065 g/mol + 4×15.999g/mol + 7×2×1.008g/mol + 7×15.999 g/mol = 246.471 g/mol

Therefore, moles of MgSO₄⋅7H₂O = 20.0g / 246.471 g/mol = 0.0811 moles

2) Now calculate the number of moles of water, using the ratios derived from the chemical formula:

7 moles of H₂O / 1 mole of MgSO₄⋅7H₂O = x / 0.0811 moles of MgSO₄⋅7H₂O

⇒ x = 0.0811 × 7 moles H₂O = 0.568 moles H₂O

3) Convert moles of H₂O to grams:

Number of moles = mass in grams × molar mass = 0.568 moles × 18.015 g/mol = 10.2 g

4) Thus, the remaining mass is 20.0g - 10.2g = 9.8g

You might be interested in

Modern commercial airliners are largely made of aluminum, a light and strong metal. But the fact that aluminum is cheap enough t

lorasvet [956]

Respuesta:

Un avión fabricado con aluminio puede transportar una mayor cantidad de pasajeros comparado con uno de acero.

Explicación:

La masa total que el avión es capaz de levantar es:

$m_{tot}=m_{fuselage}+m_{passangers}$

Para el aluminio:

$m_{tot}=m_{fus-Al}+m_{pas-Al}$

$m_{fus-Al}=\delta _{Al}*V_{fuselage}$

$V_{fuselage}=\frac{\pi *L}{4}*[D^2-(D-e)^2]$

donde:

L es longitud
D es diámetro
e es grosor

$m_{tot}=\delta _{Al}*\frac{\pi *L}{4}*[D^2-(D-e)^2]+m_{pas-Al}$

Para el acero (mismo procedimiento):

$m_{tot}=\delta _{Steel}*\frac{\pi *L}{4}*[D^2-(D-e)^2]+m_{pas-Steel$

Sabiendo que la masa total que el avión puede levantar es constante y que el aluminio tiene una densidad menor que la del acero, podemos afirmar que el avión de aluminio puede levantar un mayor número de pasajeros.

También es posible estimar un peso promedio de los pasajeros para calcular cuántos podría soportar.

5 0

14 days ago

A student puts 0.020 mol of methyl methanoate into an empty and rigid 1.0 L vessel at 450 K. The pressure is measured to be 0.74

KiRa [971]

Explanation:

Initial moles of ethanoic acid = 0.020 mol

At equilibrium, half of the ethanoic acid molecules have reacted.

Thus, moles of ethanoic acid reacted = 0.020 mol * (50% / 100%)

= 0.010 mol

Moles of ethanoic acid remaining = 0.020 mol - 0.010 mol = 0.010 mol

The moles of product $(CH3COOH)^{2}$ gas formed are determined as follows:

0.010 mol CH3COOH * (1 mol $(CH3COOH)^{2}$ / 2 mol CH3COOH)

= 0.005 mol $(CH3COOH)^{2}$

Consequently, the total moles of gas present in the vessel at equilibrium are 0.010 mol CH3COOH and 0.005 mol $(CH3COOH)^{2}$

Total gas moles at equilibrium = 0.010 mol + 0.005 mol = 0.015 mol

Next, let’s determine the pressure:

0.020 mol of gas has a pressure of 0.74 atm; so under the same conditions, we find the pressure exerted by 0.015 mol of gas:

P1/n1 = P2/n2

P2 = P1*(n2 / n1)

= 0.74 atm * (0.015 mol / 0.020 mol)

= 0.555 atm

4 0

8 days ago

The fuel used in many disposable lighters is liquid butane, C4H10. Butane has a molecular weight of 58.1 grams in one mole. How

KiRa [971]

First convert grams of C4H10 to moles using its molar mass of 58.1 g/mol: 3.50 g C4H10 × (1 mol C4H10 / 58.1 g C4H10) = 0.06024 mol C4H10 Next convert moles to molecules using Avogadro’s number: 0.06024 mol C4H10 × (6.022×10^23 molecules C4H10 / 1 mol C4H10) = 3.627×10^22 molecules C4H10 Each butane molecule contains 4 carbon atoms, so: 3.627×10^22 molecules C4H10 × (4 atoms C / 1 molecule C4H10) = 1.45×10^23 carbon atoms present.

7 0

16 days ago

Read 2 more answers

Suppose that a certain fortunate person has a net worth of $77.0 billion ($). If her stock has a good year and gains $3.20 billi

VMariaS [1037]

Answer:

The revised net worth rounded to three significant figures is $80.2 billion.

The donation to charity amounts to $100,250,000.

Explanation:

Initial net worth is $77.0 billion.

Stock gains are $3.20 billion.

Calculating new net worth: $77.0 billion + $3.20 billion = $80.20 billion.

Hence, new net worth to three significant figures is $80.2 billion.

One-eighth of a percent is calculated as (1/8 x 1) / 100 = 0.00125.

The charitable contribution amounts to 0.00125 X $80.2 billion = $100,250,000.

Alternatively, $80,200,000,000 divided by 100 results in $802,000,000.

3 0

9 days ago

Yasir wants to determine if there is a relationship between room color and sleep. Based on his research, Yasir makes an educated

Tems11 [846]

Yasir wished to explore how sleep relates to room color. He conducted necessary preliminary research and formed a hypothesis suggesting individuals doze off faster in blue-painted rooms compared to those painted in yellow. Yasir surveyed several individuals about their color preference—yellow or blue—and utilized their feedback to assess the validity of his hypothesis. However, he did not conduct an actual experiment to examine the impact of room color on sleep, and he failed to clearly define the variables that should have been part of his experiment.

Hence, the correct answer would be,

An experiment that directly tests the hypothesis

Variables to be tested by an experiment

3 0

6 days ago

Read 2 more answers