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3 years ago

Select all correct answers.

Chemistry

1 answer:

Jlenok [28]3 years ago

7 0

Answer: It showed that all atoms contain electrons.

Explanation:

J.J. Thomson's experiments inside a cathode ray tube in the presence of an electric field showed that all atoms contain tiny negatively charged subatomic particles "electrons".

Also, Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup."

Furthermore, Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny positively-charged nucleus.

Then, Rutherford proposed the nuclear model of the atom based on these results.

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What mass of CO2 in grams will form 8.94 g O2 completely react?

VLD [36.1K]

Through ratio and proportion, for every mole of O2, there is also a mole equivalent of CO2. In this case, we divide first 8.94 g O2 by 32 g/mol to convert the mass to mole. That is equivalent to 0.279375 mol which is also the amount of CO2. Multiplied by 44g/mol which is the molar mass of CO2, the answer is 12.29 grams CO2.

8 0

3 years ago

In a student experiment, the empirical formula of a copper halide was found by adding aluminum metal to an aqueous solution of t

Radda [10]

Answer: The empirical formula for the given compound is $CuCl_3$

Explanation:

We are given:

Mass of copper chloride in 1 L or 1000 mL of solution = 42.62 grams

Taking Trial A:

Volume of solution = 49.6 mL

Applying unitary method:

In 1000 mL of solution, the mass of copper chloride present is 42.62 grams

So, in 49.6 mL of solution, the mass of copper chloride will be = $\frac{42.62}{1000}\times 49.6=2.114g$

We are given:

Mass of filter paper = 0.908 g

Mass of filter paper + copper = 1.694 g

Mass of copper = [1.694 - 0.908] g = 0.786 g

Mass of chlorine in the sample = [2.114 - 0.786]g = 1.328 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Copper = $\frac{\text{Given mass of Copper}}{\text{Molar mass of Copper}}=\frac{0.786g}{63.5g/mole}=0.0124moles$

Moles of Chlorine = $\frac{\text{Given mass of Chlorine}}{\text{Molar mass of Chlorine}}=\frac{1.328g}{35.5g/mole}=0.0374moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.0124 moles.

For Copper = $\frac{0.0124}{0.0124}=1$

For Chlorine = $\frac{0.0374}{0.0124}=3.02\approx 3$

Step 3: Taking the mole ratio as their subscripts.

The ratio of Cu : Cl = 1 : 3

Hence, the empirical formula for the given compound is $CuCl_3$

3 0

3 years ago

Calculate the molarity of the two solutions.

beks73 [17]

Answer:

A = Molarity = 0.22 M

B = Molarity = 0.36 M

Explanation:

Given data:

For first solution:

number of moles = 0.550 mol

Volume of solution = 2.50 L

Molarity = ?

Molarity:

Formula:

Molarity = number of moles of solute / volume of solution in L.

Molarity = 0.550 mol / 2.50 L

Molarity = 0.22 M

For second solution:

Mass of NaCl = 15.7 g

Volume of solution = 709 mL or 709/1000 = 0.709 L

Molarity = ?

Solution:

Number of moles = mass / molar mass

Number of moles = 14.7 g/ 58.44 g/mol

Number of moles = 0.252 mol

Molarity:

Molarity = number of moles of solute / volume of solution in L.

Molarity = 0.252 mol / 0.709 L

Molarity = 0.36 M

8 0

3 years ago

Nitrogen has an atomic number of 7; therefore, it has ______ electrons in its outermost electron shell.

galina1969 [7]

it has 5 electrons in it's outermost shell.
s 2e- , p 5e-

4 0

3 years ago

Convert the following to grams 0.500 moles of (NH4)2CO3

steposvetlana [31]

Molar mass (NH₄)₂CO₃ = 96.09 g/mol

1 mole ---------> 96.09 g
0.500 moles ----> ?

0.500 * 96.09 = 48.045 g of (NH₄)₂CO₃

hope this helps!

5 0

3 years ago