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MariettaO [177]
2 years ago
9

Help asap for brainlist

Chemistry
1 answer:
oksian1 [2.3K]2 years ago
6 0

Answer:

Group 17

Explanation:

You might be interested in
The combustion of ethane (C2H6) produces carbon dioxide and steam. 2C2H6(g)+7O2(g)⟶4CO2(g)+6H2O(g) How many moles of CO2 are pro
Gwar [14]

Answer: 11.2 moles of CO_2 are produced when 5.60 mol of ethane is burned in an excess of oxygen.

Explanation:

The combustion of ethane is represented using balanced chemical equation:

2C_2H_6(g)+7O_2(g)\rightarrow 4CO_2(g)+6H_2O(g)

As oxygen is preset in excess, ethane acts as the limiting reagent as it limits the formation of product.

According to stoichiometry :

2 moles of propane produces 4 moles of carbon dioxide

Thus 5.60 moles of propane will produce=\frac{4}{2}\times 5.60=11.2 moles of carbon dioxide

Thus 11.2 moles of CO_2 are produced when 5.60 mol of ethane is burned in an excess of oxygen.

6 0
3 years ago
A solution is made by dissolving 4.35 g of glucose (C6H1206) in 25.0 mL of water at 25 °C.Calculate the molality of glucose in t
Roman55 [17]

Answer:

The molality is unchanged (0.96 molal)

Explanation:

<u>Step 1: </u>Data given

mass of glucose = 4.35 grams

volume of water = 25.0 mL

Density of water = 1.00 g/mL

Molar mass of glucose = 180.156 g/mol

<u>Step 2:</u> Calculate number of moles

moles of glucose = mass of glucose / Molar mass of glucose

moles of glucose = 4.35 grams / 180.156 g/mol

moles of glucose = 0.024 moles

<u>Step 3:</u> Calculate mass of water

mass = density * volume

mass of water = 1.00 g/mL * 25.0 mL

mass of water = 25 g = 0.025 kg

<u>Step 4</u>: Calculate molality

molality = Number of moles / mass of water

molality = 0.024 moles / 0.025 kg

molality = <u>0.96 molal</u>

Suppose you take a solution and add more solvent, so that the original mass of solvent is doubled.

This means double mass of water = 2*0.025 kg = 0.050 kg

Now molality is 0.024 moles / 0.050 kg = 0.48 molal

When the mass of solvent is doubled, the molality is halved from 0.96 molal to <u>0.48 molal</u>

You take this newsolution and add more solute, so that the original mass of the solute is doubled.

This means double mass of glucose = 2*4.35 g = 8.70 g

8.70 grams of glucose = 8.7 grams * 180.156 g/mol = 0.048 moles

molality = 0.048 moles / 0.050 kg = <u>0.96 molal</u>

The molality is unchanged

5 0
4 years ago
How many kilowatt-hours of electricity are used to produce 3.00 kg of magnesium in theelectrolysis of molten MgCl2 with an appli
Llana [10]

Answer:

There is 29.8 kilowatt hours needed.

Explanation:

Step 1: Data given

Mass of Magnesium = 3.00 kg

Molar mass of magnesium = 24.31 g/mol

Applied emf = 4.50 V (= 4.50 J/C)

Step 2: Calculate moles of Magnesium

Moles = Mass Mg / Molar mass Mg

Moles Mg = 3000 grams / 24.31 g/mol

Moles Mg =  123.4 moles

Step 3: Calculate  how many electrons are needed to produce the magnesium.

The ionic equation for the reduction of Mg^2+ :

Mg^2+   +   2e^-  →   Mg

Every mole of Mg requires 2 mol of electrons.

For 123.4 mol of Mg, we have 246.8 mol of electrons.

Step 3: Find how many coulombs are involved.

The Faraday constant = 96500 couloumbs

1 mole of electrons is 96500 coulombs.

246.8 mol of electrons need  2.38 *10^7 Coulombs

Step 4: Calculate kilowatt-hours of electricity needed

2.38 * 10^7 C * 4.5 J/C = 10.7 * 10^7 J

10.7 * 10^7 J * ( 1 kW-h-/ 3.6*10^6 J ) = 29.8 kWh

There is 29.8 kilowatt hours needed.

5 0
3 years ago
A 2uc charge is at rest in a magnetic field of 2 t pointing along the x-axis. what is the force acting on this charge in the mag
sp2606 [1]
Zero...bcz force which acts on this charge is f=qvB q=2uc ,B=2T and v=o
so,f=zero...
4 0
4 years ago
Suppose you have 81.8 g of Cd. How many Cd atoms are present? Report your answer in scientific notation using the format of 6.02
Lostsunrise [7]

Answer:

1. number of Cd atoms = 4.384 × 10²³

2. number of moles of Ti = 0.817 mol

3. molar mass of C₇H₆O₃ = 138.077 g/mol

4. moles of Sildenafil = 0.249 mmol

Explanation:

1. given data

mass of Cd = 81.8 g

number of Cd atoms = ?

molar mass of Cd = 112.411 g/mol

Solution

1st we find out the number of moles of Cd

<em>         number of moles = mass / molar mass </em>

 number of moles of Cd = 81.8 g / 112.411 g.mol⁻

 number of moles of Cd = 0.728 mol

Now we find out the number of Cd atoms

<em>       number of atoms = moles × 6.022 × 10²³</em>

 number of Cd atoms = 0.728 (6.022 × 10²³)

 number of Cd atoms = 4.384 × 10²³

 

2. Given data

Mass of Ti = 39.1 g

moles = ?

molar mass Ti = 47.867 g/mol

Solution

Now we will find out the number of moles

<em>         number of moles = mass / molar mass </em>

 number of moles of Ti = 39.1 g / 47.867 g.mol⁻

 number of moles of Ti = 0.817 mol

3. Given data

chemical formula of Salicylic acid  = C₇H₆O₃

molar mass of salicylic acid = ?

molar mass of carbon = 12.011

molar mass of hydrogen = 1.008

molar mass of oxygen = 15.999

<em>         molar mass of  molecule = number of moles of atoms × molar mass of atoms</em>

  molar mass of C₇H₆O₃ = 7 (12.011) + 6 (1) + 3 (16)

  molar mass of C₇H₆O₃ = 84.077 g + 6 g + 48 g

  molar mass of C₇H₆O₃ = 138.077 g/mol

4. Given data

molar mass of Sildenafil = 474.5828 g/mol

mass given = 0.118 g

moles of Sildenafil = ?

Solution

Now we find out the number of moles

<em>          number of moles = mass / molar mass </em>

<em>   </em>number of moles Sildenafil = 0.118 g / 474.5828 g/mol

  number of moles Sildenafil = 0.0003 mol

as this is very small amount we convert it into millimoles

           <em>millimoles = moles × 1000</em>

    millimoles of Sildenafil = 0.000249 × 1000

    millimoles of Sildenafil = 0.249 mmol

4 0
3 years ago
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