2. True or false? The complete ionic equation contains only those substances directly involved in

Which of the following statements is true?

goldfiish [28.3K]

Answer:

D

Explanation:

Heat sometimes gets "lost" when work is done

4 0

2 years ago

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Evaluate the Lewis structures below and pick the statements that best describes the accuracy of each of the structures. There ma

Artyom0805 [142]

Answer:

The structures shown by dots and lines to give the exact number of electrons in the outer most shell is explained by Lewis Structures.

Explanation:

Lewis structures are those structures in which the diagram is shown using the electron representation. They are easy to understand as the diagram completely depicts where the electrons are shared and where they are transferred. The diagram also explains where there is a single bond and where there is a di covalent bond or tri covalent bond explaining where the single , double or triple electron pair is shared. The electrons are shown by dots or lines.

For example CCl₄ can be shown as follows

..

.. Cl..

.. ..

..Cl..----------C----------..Cl..

..

.. Cl..

The picture shows that each chlorine has six electrons in its outer shell and then a pair of electron is shared with carbon forming a single covalent bond.

Similarly methane CH4 can also be shown.

The hydrogen has one electron and it shares an electron from carbon stabilising itself forming methane.

6 0

3 years ago

How many moles of liquid water must freeze to remove 100 kJ of heat? (ΔHf = –334 J/ g.

Juliette [100K]

First figure out how many grams must freeze and then convert the grams to moles.
Hf = -334 J/g. Convert this to KJ/g by dividing by 1000. (There are 1000 Joules in a kJ). 
Hf = -334 J/g ÷ 1000 J/kj = -0.334 kJ/g 
Now, divide 100 kJ by -0.334 kJ/g (see how the units are lining up?) 
100 kJ ÷ -0.334 kJ/g = 299 g 
Now convert this to moles by dividing by the molecular weight of water (18.0g/mole). 
299 ÷ 18.0 = 16.6 moles

5 0

3 years ago

Suppose that Daniel has a 3.00 3.00 L bottle that contains a mixture of O 2 O2 , N 2 N2 , and CO 2 CO2 under a total pressure of

Alenkinab [10]

Answer:

Partial pressure O₂ → 2.74 atm

Explanation:

Let's analyse the data given:

Volume → 3L

In the bottle there is a mixture of gases that contains, O₂, N₂ and CO₂.

Total pressure is 4.80 atm

Let's apply the Ideal Gases Law to determine the total moles of the mixture

P . V = n . R. T

4.80 atm . 3L = n . 0.082 . 273K

n = 4.80 atm . 3L / 0.082 . 273K → 0.643 moles

We apply the concept of mole fraction:

Mole fraction of a gas X = moles of gas X / Total moles

Mole fraction of a gas X = Partial pressure X / Total pressure

In a mixture, sum of mole fraction of each gas = 1

We determine mole fraction of N₂ → 0.230 / 0.643 = 0.357

We determine mole fraction of CO₂ → 0.350 atm / 4.80 atm = 0.0729

1 - mole fraction N₂ - mole fraction CO₂ = mole fraction O₂

1 - 0.357 - 0.0729 = 0.5701 → mole fraction O₂

We replace in the formula: Mole fraction O₂ = Partial pressure O₂ / 4.80 atm

0.5701 . 4.80 atm = Partial pressure O₂ → 2.74 atm

5 0

2 years ago

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Calcium is an element. What is the smallest particle of calcium that has the same chemical properties of calcium?

Verdich [7]

Answer:

A. An Atom

Explanation:

An atom is the smallest particle of an element, having the same chemical properties as the bulk element.

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2 years ago

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