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3 years ago

Please Help Me on this!!!! I'll Mark Brainliest!!!!! Thanks!!!!!!

Chemistry

2 answers:

makvit [3.9K]3 years ago

8 0

Answer:

15.999amu

Explanation:

There is way more O16 than any other, so O17 and O18 affect it very little.

Stella [2.4K]3 years ago

5 0

Answer:

The answer is 15.999 amu

Explanation:

Data:

mO16 = 15.995 amu

mO17 = 16.999 amu

mO18 = 17.999 amu

%O16 = 99.757%

%O17 = 0.038%

%O18 = 0.205%

The molecular mass of oxygen is going to be equal to:

$mO = \frac{(mO16xpercentO16)+(mO17xpercentO17)+(mO18xpercentO18)}{100}$

replacing, we have:

$mO = \frac{(15.995x99.757)+(16.999x0.038)+(17.999x0.205)}{100} = 15.999489 amu$

this is approximately 15.999 amu

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Calculate the grams of so2 gas present at stp in a 5.9 l container.

nata0808 [166]

Answer: The mass of sulfur dioxide gas at STP for given amount is 16.8 g

Explanation:

At STP conditions:

22.4 L of volume is occupied by 1 mole of a gas.

So, 5.9 L of volume will be occupied by = $\frac{1mol}{22.4L}\times 5.9L=0.263mol$

Now, to calculate the mass of a substance, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of sulfur dioxide gas = 0.263 mol

Molar mass of sulfur dioxide gas = 64 g/mol

Putting values in above equation, we get:

$0.263mol=\frac{\text{Mass of sulfur dioxide gas}}{64g/mol}\\\\\text{Mass of sulfur dioxide gas}=(0.263mol\times 64g/mol)=16.8g$

Hence, the mass of sulfur dioxide gas at STP for given amount is 16.8 g

7 0

3 years ago

A 1.2516 gram sample of a mixture of caco3 and na2so4 was analyzed by dissolving the sample and completely precipitating the ca

Dennis_Churaev [7]

Answer:

0.009725 moles of H2C2O4

0.009725 moles CaCO3

Mass percentage = 77.77%

Explanation:

Step 1: The balanced equation

2MnO4- +5C2H2O4+6H+ →2Mn2+ +10CO2+8H2O

We can see that for 2 moles of Mno4- consumed , there is 5 moles of C2H2O4 needed and 6 moles H+ to produce 2 moles Mn2+, 10 moles of CO2 and 8 moles of H2O

Step 2: Calculate moles of MnO4-

Molarity = Moles/volume

Moles of Mno4- = Molarity of MnO4- * Volume of Mno4-

Moles of Mno4- = 0.1092M * 35.62 *10^-3 L

Moles of MnO4- = 0.00389 moles

Step 3: Calculate moles of H2C2O4

Since there is needed 5 moles of C2H2O4 to consume 2 moles of MnO4-

then for 0.00389 moles of MnO4-, there is 5/2 *0.00389 = 0.009725 moles of H2C2O4

Step 4: Calculate moles of CaCO3

moles of H2C2O4 = moles CaCO3, therefore, 0.009725 moles H2C2O4 = 0.009725 moles CaCO3

Step 5: Calculate mass of CaCO3

Molar mass of CaCO3 = 100.09 g/mole

Mass of CaCO3 = moles of CaCO3 * Molar mass of CaCO3

Mass of CaCO3 = 0.009725 moles * 100.09 g/mole = 0.9734 g

Step 6: Calculate percentage by weight of CaCO3

Mass of CaCO3 = 0.9734g

Mass of original sample = 1.2516g

Mass percentage = 0.9734/1.2516 *100% = 77.77%

6 0

3 years ago

Sort these six events from the earliest to the most recent. 1. Democritus proposes the existence of atoms 3rd 2. Dalton's atomic

Nitella [24]

Explanation:

1. Democritus proposes the existence of atoms

2. Dalton's atomic theory

3. J. J. Thomson discovers the electron

4. Rutherford's gold foil experiment

5. Bohr model

6. Schrödinger's Wave Mechanics model of the atom

The first idea about matter containing atoms dates back to Greek philosophers. One of them was Democritus .

In 1808 Dalton put forward his atomic theory

In 1897 J.J Thomson discovered cathode rays using his gas discharge tube experiment.

In 1911, Ernest Rutherford proposed the nuclear model of the atom using experiments on the gold foil.

Neils Bohr in 1913 suggested his own atomic model

Erwin Schrodinger formulated the wave equation of electrons

Learn more;

Dalton atomic theory brainly.com/question/1979129

Rutherford gold foil experiment brainly.com/question/1859083

#learnwithBrainly

4 0

3 years ago

How can you figure out the properties of a star?

Firlakuza [10]

Answer:

Measuring distances to stars through stellar parallax. Measuring distances to stars through the moving cluster method. Astronomers measure the temperature of a star by looking at the star's color and its spectrum. The apparent brightness of a star tells how bright it seems to us

Explanation:

3 0

3 years ago

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What chemical property must argon have to make it a suitable choice for light bulbs?

wlad13 [49]

Argon is a suitable choice for light bulbs because it's inert. Compared to a reactive gas like oxygen, the metal filimant would burn up in a reactive enviroment, which is why a noble gas is used.

8 0

3 years ago