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3 years ago

How do you find the molecular formula for a compound

1 answer:

5 0

Start with the number of grams of each element, given in the problem.Convert the mass of each element to moles using the molar mass from the periodic table.Divide each mole value by the smallest number of moles calculated.Round to the nearest whole number.

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Which of the following (with specific heat capacity provided) would show the smallest temperature change upon gaining 200.0 J of

Brut [27]

Answer: The smallest temperature change is shown by water.

Explanation:

To calculate the heat absorbed or released, we use the equation:

$q=mC\times \Delta T$ ......(1)

where,

q = heat absorbed = 200.0 J

m = mass of the substance

C = specific heat of substance

$\Delta T$ = change in temperature

As, the same amount of heat is getting absorbed in all the cases. So, the change in temperature will depend on the product of mass and specific heat.

For the given options:

Option a: 50.0 g Fe, $C_{Fe}=0.449J/g^oC$

We are given:

$m=50.0g\\C_{Fe}=0.449J/g^oC$

Putting values in equation 1, we get:

$200.0J=50.0g\times 0.449J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{50\times 0.449}=8.99^oC$

Change in temperature = 8.99°C

Option b: 50.0 g water, $C_{water}=4.18J/g^oC$

We are given:

$m=50.0g\\C_{water}=4.18J/g^oC$

Putting values in equation 1, we get:

$200.0J=50.0g\times 4.18J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{50\times 4.18}=0.96^oC$

Change in temperature = 0.96°C

Option b: 25.0 g Pb, $C_{Pb}=0.128J/g^oC$

We are given:

$m=50.0g\\C_{Pb}=0.128J/g^oC$

Putting values in equation 1, we get:

$200.0J=25.0g\times 0.128J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{25\times 0.128}=62.5^oC$

Change in temperature = 62.5°C

Option d: 25.0 g Ag, $C_{Ag}=0.235J/g^oC$

We are given:

$m=25.0g\\C_{Ag}=0.235J/g^oC$

Putting values in equation 1, we get:

$200.0J=25.0g\times 0.235J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{25\times 0.235}=34.04^oC$

Change in temperature = 34.04°C

Option e: 25.0 g granite, $C_{granite}=0.79J/g^oC$

We are given:

$m=25.0g\\C_{Fe}=0.79J/g^oC$

Putting values in equation 1, we get:

$200.0J=25.0g\times 0.79J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{25\times 0.79}=10.13^oC$

Change in temperature = 10.13°C

Hence, the smallest temperature change is shown by water.

5 0

3 years ago

Since helium is lighter than air, it is difficult to measure the mass of a sample, so to find out the mass of helium in a birthd

d1i1m1o1n [39]

Answer:

0.7457 g is the mass of the helium gas.

Explanation:

Given:

Pressure = 3.04 atm

Temperature = 25.0 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T₁ = (25.0 + 273.15) K = 298.15 K

Volume = 1.50 L

Using ideal gas equation as:

$PV=nRT$

where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the equation as:

3.04 atm × 1.50 L = n × 0.0821 L.atm/K.mol × 298.15 K

⇒n = 0.1863 moles

Molar mass of helium = 4.0026 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$0.1863\ mole= \frac{Mass}{4.0026\ g/mol}$

$Mass_{He}= 0.7457\ g$

0.7457 g is the mass of the helium gas.

6 0

2 years ago

Write an expression for "7 less than y."

victus00 [196]

Answer:

y-7

Explanation:

4 0

3 years ago

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Chemistry neeeeeeed help!

ryzh [129]

<h3> ANSWER </h3>

4. O²-

<h3>EXPLANATION </h3>

O²- has 16 electrons while Ne has 18 electrons. O²- is a molecule that has one electron added to each atom, meaning that there are two extra electrons which makes O²- the same electron configuration as of Ne atom.

8 0

2 years ago

Give the major force between ethanol and water. dipole-dipole dispersion hydrogen bonding ion-ion ion-dipole

Komok [63]

Answer:

HYDROGEN BONDING

Explanation:HYDROGEN BONDING is the major intermolecular force and interaction taking place when water and ethanol are mixed.

Hydrogen bond is a weak inter-molecular force of attraction which occurs when the partially charged Negative end of an oxygen atom from one oxygen molecule attracts and interacts with the partially charged Positive end of the Hydrogen atom in another Molecule, Hydrogen bonds are also known as dipole-dipole bonds.

7 0

2 years ago

Read 2 more answers