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4 years ago

13. Hydrogen and helium have both been used to fill balloons. Which property of helium

Chemistry

2 answers:

Zolol [24]4 years ago

8 0

Answer:

Helium is lighter than Hydrogen and Helium is a much safer gas.

horrorfan [7]4 years ago

7 0

Answer:

Helium gas is known to be very light which makes it a preferred choice to hydrogen. Helium has low boiling point, low density, low solubility, high thermal conductivity and inertness. Since it is less dense, it is considered suitable for filling balloons.

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What are atoms made of

Olegator [25]

Protons, neutrons, and electrons.

7 0

3 years ago

Read 2 more answers

Use the drop-down menus to classify each of the following as an addition, substitution, elimination, or

OLga [1]

Answer:

CH3CHO+H2O → CH3OCH3 - addition

CH,CICH CI + Zn → C2H4 + ZnCl2 - elimination

CH3CH3Br + OH – CH3CH3OH + Br - substitution

2CH2COOH >>(CH3CO)20 + H20 - condensation

Explanation:

An addition reaction is a reaction in which a specie is added across the double bond as we can see in CH3CHO+H2O → CH3OCH3.

In an elimination reaction, a small molecule is lost from a saturated compound to form the corresponding unsaturated compound as in CH,CICH CI + Zn → C2H4 + ZnCl2

In a substitution reaction, a chemical moiety replaces another in a molecule as in; CH3CH3Br + OH – CH3CH3OH + Br .

A condensation reaction is in which two molecules are joined together to form a bigger molecule as in; 2CH2COOH >>(CH3CO)20 + H20.

4 0

3 years ago

What is the maximum amount of kcl that can dissolve in 200g of water?

Likurg_2 [28]

The solubility of potassium chloride in at room temperature is approximately 34 g per 100 g of water. Therefore, the maximum amount that could be dissolved would be 34/100 ( 200) = 68 g of KCl. When more than this amount is added, excess potassium would not dissolve forming crystals in the solution.

8 0

3 years ago

An ideal gas (C}R), flowing at 4 kmol/h, expands isothermally at 475 Kfrom 100 to 50 kPa through a rigid device. If the power pr

Zina [86]

<u>Answer:</u> The rate of heat flow is 3.038 kW and the rate of lost work is 1.038 kW.

<u>Explanation:</u>

We are given:

$C_p=\frac{7}{2}R\\\\T=475K\\P_1=100kPa\\P_2=50kPa$

Rate of flow of ideal gas , n = 4 kmol/hr = $\frac{4\times 1000mol}{3600s}=1.11mol/s$ (Conversion factors used: 1 kmol = 1000 mol; 1 hr = 3600 s)

Power produced = 2000 W = 2 kW (Conversion factor: 1 kW = 1000 W)

We know that:

$\Delta U=0$ (For isothermal process)

So, by applying first law of thermodynamics:

$\Delta U=\Delta q-\Delta W$

$\Delta q=\Delta W$ .......(1)

Now, calculating the work done for isothermal process, we use the equation:

$\Delta W=nRT\ln (\frac{P_1}{P_2})$

where,

$\Delta W$ = change in work done

n = number of moles = 1.11 mol/s

R = Gas constant = 8.314 J/mol.K

T = temperature = 475 K

$P_1$ = initial pressure = 100 kPa

$P_2$ = final pressure = 50 kPa

Putting values in above equation, we get:

$\Delta W=1.11mol/s\times 8.314J\times 475K\times \ln (\frac{100}{50})\\\\\Delta W=3038.45J/s=3.038kJ/s=3.038kW$

Calculating the heat flow, we use equation 1, we get:

[ex]\Delta q=3.038kW[/tex]

Now, calculating the rate of lost work, we use the equation:

$\text{Rate of lost work}=\Delta W-\text{Power produced}\\\\\text{Rate of lost work}=(3.038-2)kW\\\text{Rate of lost work}=1.038kW$

Hence, the rate of heat flow is 3.038 kW and the rate of lost work is 1.038 kW.

4 0

3 years ago

Write the lewis structure for mgi2. draw the lewis dot structure for mgi2. include all lone pairs of electrons.

viktelen [127]

Lewis Structure is drawn in following steps,

1) Calculate Number of Valence Electrons:

# of Valence electrons in Mg = 2
# of Valence electrons in I     = 7
# of Valence electrons in I     = 7
---------
Total Valence electrons = 16

2) Draw Mg as a central atom surround it by two atoms of Iodine.

3) Connect each Iodine atom to Mg, and subtract two electrons per bond. In this case we will subtract 4 electrons from total valence electrons. i.e.

Total Valence electrons 16
- Four electrons - 4
----------
    12

4) Now start adding the remaining 12 electrons on more electronegative atoms i.e. Iodine.

The final lewis structure formed is as follow,

4 0

3 years ago