The atomic number ALWAYS equals the number of <br> protons<br> neutrons<br> electons

A 44.8 g rhodium sample contains how many rhodium atoms

Tresset [83]

Answer:

2.63*10^23

Explanation:

1 mol rhodium = 102.91

44.8g/1 mol * 1 mol/ 102.91mol * 6.022*10^23/1 mol =

2.63*10^23

6 0

3 years ago

Kia is doing an experiment in science lab. She is given a beaker containing 100 g of liquid. The beaker has markings on the side

Semmy [17]

Kia's remaining water has a mass of 50g. You can set it up as a proportion knowing that 100ml of water has a mass of 100g and thus 50ml of water would weight 50g

7 0

2 years ago

Read 2 more answers

3.5g of a Certain compound X, known to be made of carbon, hydrogen, and perhaps oxygen, and to have a molecular molar mass of 15

shutvik [7]

Answer:

C₅H₁₀O₅

Explanation:

1. Calculate the mass of each element in 2.78 mg of X.

(a) Mass of C

$\text{Mass of C} = \text{5.13 g CO}_{2}\times \dfrac{\text{12.01 g C}}{\text{44.01 g }\text{CO}_{2}}= \text{1.400 g C}$

(b) Mass of H

$\text{Mass of H} = \text{2.10 g H$_{2}$O}\times \dfrac{\text{2.016 g H}}{\text{18.02 g H$_{2}$O}} = \text{0.2349 g H}$

(c) Mass of O

Mass of O = 3.5 - 1.400 - 0.2349 = 1.87 g

2. Calculate the moles of each element

$\text{Moles of C = 1400 mg C}\times\dfrac{\text{1 mmol C}}{\text{12.01 mg C }} = \text{116.6 mmol C}\\\\\text{Moles of H = 234.9 mg H} \times \dfrac{\text{1 mmol H}}{\text{1.008 mg H}} = \text{233.1 mmol H}\\\\\text{Moles of O = 1870 mg O} \times \dfrac{\text{1 mmol O}}{\text{16.00 mg O}} = \text{116 mmol O}$

3. Calculate the molar ratios

Divide all moles by the smallest number of moles.

$\text{C: } \dfrac{116.6}{116.6}= 1\\\\\text{H: } \dfrac{233.1}{116.6} = 1.999\\\\\text{O: } \dfrac{116}{116.6} = 1.00$

4. Round the ratios to the nearest integer

C:H:O = 1:2:1

5. Write the empirical formula

The empirical formula is CH₂O.

6. Calculate the molecular formula.

EF Mass = (12.01 + 2.016 + 16.00) u = 30.03 u

The molecular formula is an integral multiple of the empirical formula.

MF = (EF)ₙ

$n = \dfrac{\text{MF Mass}}{\text{EF Mass }} = \dfrac{\text{150 u}}{\text{30.03 u}} = 5.00 \approx 5$

MF = (CH₂O)₅ = C₅H₁₀O₅

The molecular formula of X is C₅H₁₀O₅.

8 0

3 years ago

Propane (c3h8) is burned in oxygen to produce carbon dioxide and water. the heat of combustion of propane is -2012 kj/mole. how

Olegator [25]

$C_{3} H_{8} + 5 O_{2} ---\ \textgreater \ 3CO_{2} +4H_{2}O (-2012 \frac{kJ}{mol} )


3 mol 10 mol


C_{3}H_{8} is /excess /reactant

because 3 mol propane require 15 mol oxygen (by reaction)

5 mol oxygen ---1 mol propane, so

10 mol oxygen ---2 mol propane

Only 2 mole propane will be burned,

so 

2012 ( kJ/mol)*2 mol =4024 KJ heat will be given off

Correct answer is number 4.


$

5 0

2 years ago

Fission and Fusion of Atomic Nuclei:

bogdanovich [222]

Answer:

C B A D

Explanation:

6 0

3 years ago

The atomic number ALWAYS equals the number of protons neutrons electons