Calculate the volume in mL of 53.2 g of .251M solution of HCl. <br> Show work please

What is the mass of 0.55 mole<br> of magnesium chloride?

Gala2k [10]

Answer:

SYMBOLS, FORMULAS AND MOLAR MASSES

OBJECTIVES

1. To correctly write and interpret chemical formulas

2. To calculate molecular weights from chemical formulas

3. To calculate moles from grams using chemical formulas

INTRODUCTION

Part I. Symbols and formulas

An element is a homogeneous pure substance made up of identical atoms. All matter is made

up of elements and, since chemistry is the study of matter, it is convenient to use symbols to represent

the elements rather than using the entire name.

By international agreement, specific symbols are assigned to each element (Note: This means

that while names of the elements vary with language, symbols are constant throughout the world.) Each

element is assigned a one- or two-letter symbol. The first letter is capitalized, the second (if there is

one) is not. While this often seems trivial, it is in fact a very important point. For example, in chemical

language Co represents cobalt, which is a metal and an element, while CO represents carbon monoxide,

a compound which is a colorless, odorless gas! Even when there is not an obvious correspondence,

for instance "MN", it can cause confusion. Do you mean the element manganese? Did you forget a

letter and mean something else? Are you using "M" to represent something else entirely? Chemists

sometimes use "M" to represent any metal. It is well worth the trouble to memorize the symbols for

common elements.

Since compounds consist of elements, the chemical formulas of compounds also consist of

elements with subscripts used to denote the number of atoms per molecule. If there is no subscript, it is

implied that there is one of that kind of atom. Ones never appear in chemical formulas. Not only do

subscripts denote ratios of atoms, they also denote the ratio of moles of element to one mole of

compound. Parentheses can be used to show groups of atoms, with the subscripts showing how many

groups there are. Parentheses are not used if there is only one group.

Examples: For one mole of the following compounds, how many moles of each element are

present?

MgCl2 1 mole Mg, 2 moles Cl

Mg(NO3)2 1 mole Mg, 2 moles N, 6 moles O

NaNO3 1 mole Na, 1 mole N, 3 mole O

AgCl 1 mole Ag, 1 mole ClPart II. Molar Masses

Each atom has a different size and therefore a different mass. The relative masses of each

element can be found on the periodic table. For example, one atom of magnesium weighs 24.31 amu

(atomic mass units). However, one mole of magnesium weighs 24.31 g. (Moles were planned that

way!) Since one mole of MgCl2 consists of one mole of magnesium and two moles of chlorine, the

mass of one mole of MgCl2 must be the sum of the masses of the elements. The mass of one mole of a

substance is called the molar mass or molecular weight.

Examples: What is the molar mass of the following compounds?

MgCl2 24.31 + 2(35.45) = 95.21 g/mol

Mg(NO3)2 24.31 + 2(14.01) + 6(16.00) = 148.33 g/mol

NaNO3 23.00 + 14.01 + 3(16.00) = 85.01 g/mol

AgCl 107.9 + 35.45 = 143.4 g/mol

(Note: Yes! You DO have to count significant figures when calculating molecular weight/molar

mass. However, the number of significant figures may vary depending on which periodic table you use.)

Chemists are generally interested in number of moles. Unfortunately, it is impossible to measure

moles directly. However, masses are easily measured, and if the chemical formula of the compound is

known, the molar mass can be used to determine the number of moles. The molar mass is defined as:

molar mass = grams/moles = g/mol (1)

Moles may be calculated by using molar mass as a conversion factor in dimensional analysis where

molar mass in grams = 1 (exactly) mole of compound (2)

This method is used in multi-step calculations. For example, if 0.873 g of MgCl2 is weighed out, it

is 9.17 x 10-3

moles.

1 mole

0.873g x 95.21 g = 9.17 x 10-3

mol MgCl2 (3)

However, 0.873 g of AgCl is only 6.09 x 10-3

mol.

1 mole

0.873g x 143.4 g = 6.09 x 10-3

mol AgCl (4)Molar mass may also be used to relate moles to grams. For example, 0.158 mol of MgCl2 is 15.2 g.

0.158 mol x 95.21 g = 15.2 g MgCl2 (5)

1 mol

Percent is used to express parts per one hundred. Usually in chemistry, it refers to

g of species of interest x 100 = % (6)

g of whole thing

Example: For the % Mg in MgCl2: In one mole of MgCl2, there are 24.31 g of Mg (molar mass of Mg,

the part we are interested in) and 95.21 g of MgCl2 (the whole thing), so %Mg in MgCl2 is

(24.31/95.21) x 100 = 25.53% Mg (7)

PROCEDURE

Work individually.

The formula for calcium phosphate is Ca3(PO4)2. Weigh about 2 g of calcium phosphate to the

nearest 0.001 g. In other words, you do not have to have exactly 2.000g, but you must know the

weight you have exactly. Acceptable results include but are not limited to: 1.985g , 2.035g, 2.314g

etc.

Be sure to report all results with the correct number of significant figures and appropriate units!

5 0

3 years ago

Does anyone know what Hydrogen's oxidation state would be if it was acting as an anion non-metal?

Ilia_Sergeevich [38]

Answer:

yeah,The oxidation state of an atom does not represent the "real" charge on that atom, or any other actual atomic property.Hydrogen has OS = +1, but adopts −1 when bonded as a hydride to metals or metalloids. Oxygen in compounds has OS = −2. This set of postulates covers .

Explanation:

3 0

3 years ago

What was the history and use of the periodic table?

cestrela7 [59]

<span>In 1669 German merchant and amateur alchemist Hennig Brand attempted to created a Philosopher’s Stone; an object that supposedly could turn metals into pure gold. He heated residues from boiled urine, and a liquid dropped out and burst into flames. This was the first discovery of phosphorus.

In 1680 Robert Boyle also discovered phosphorus, and it became public.

In 1809 at least 47 elements were discovered, and scientists began to see patterns in the characteristics.

In 1863 English chemist John Newlands divided the then discovered 56 elements into 11 groups, based on characteristics.

In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomic mass. He predicted the discovery of other elements, and left spaces open in his periodic table for them.

In 1886 French physicist Antoine Bequerel first discovered radioactivity. Thomson student from New Zealand Ernest Rutherford named three types of radiation; alpha, beta and gamma rays. Marie and Pierre Curie started working on the radiation of uranium and thorium, and subsequently discovered radium and polonium. They discovered that beta particles were negatively charged.

In 1894 Sir William Ramsay and Lord Rayleigh discovered the noble gases, which were added to the periodic table as group 0.In 1897 English physicist J. J. Thomson first discovered electrons; small negatively charged particles in an atom. John Townsend and Robert Millikan determined their exact charge and mass.

In 1900 Bequerel discovered that electrons and beta particles as identified by the Curies are the same thing.

In 1903 Rutherford announced that radioactivity is caused by the breakdown of atoms.

In 1911 Rutherford and German physicist Hans Geiger discovered that electrons orbit the nucleus of an atom.

In 1913 Bohr discovered that electrons move around a nucleus in discrete energy called orbitals. Radiation is emitted during movement from one orbital to another.

In 1914 Rutherford first identified protons in the atomic nucleus. He also transmutated a nitrogen atom into an oxygen atom for the first time. English physicist Henry Moseley provided atomic numbers, based on the number of electrons in an atom, rather than based on atomic mass.

In 1932 James Chadwick first discovered neutrons, and isotopes were identified. This was the complete basis for the periodic table. In that same year Englishman Cockroft and the Irishman Walton first split an atom by bombarding lithium in a particle accelerator, changing it to two helium nuclei.

In 1945 Glenn Seaborg identified lanthanides and actinides (atomic number >92), which are usually placed below the periodic table.</span>

8 0

3 years ago

Which type of pollution includes CFCs and smog?

Elina [12.6K]

Air pollution exist in two forms namely ozone and particle pollution. CFCs and smog are under the ozone form of pollution. Ozone type of pollution is mostly formed by reaction between the sunlight and the vapors that are emitted due to human activities.

5 0

4 years ago

Read 2 more answers

The most useful ore of aluminum is bauxite, in which Al is present as hydrated oxides, Al2O3 * xH2O.

lesantik [10]

Answer:

44.7 kWh

Explanation:

Let's consider the reduction of Al₂O₃ to Al in the Bayer process.

6 e⁻ + 3 H₂O + Al₂O₃ → 2 Al + 6 OH⁻

We can establish the following relations:

The molar mass of Al is 26.98 g/mol.
2 moles of Al are produced when 6 moles of e⁻ circulate.
1 mol of e⁻ has a charge of 96468 c (Faraday's constant).
1 V = 1 J/c
1 kWh = 3.6 × 10⁶ J

When the applied electromotive force is 5.00 V, the energy required to produce 3.00 kg (3.00 × 10³ g) of aluminum is:

$3.00 \times 10^{3} gAl.\frac{1molAl}{26.98gAl} .\frac{6mole^{-}}{2molAl}.\frac{96468c}{1mole^{-}}.\frac{5.00J}{c}.\frac{1kWh}{3.6 \times 10^{6}J} =44.7kWh$

6 0

3 years ago

Calculate the volume in mL of 53.2 g of .251M solution of HCl. Show work please