How many moles of sand (SiO2) are in 30 g of sand?

Answer:

(c) only solute present

Explanation:

In chemistry, the mole fraction, denoted by X, refers to the number of moles of a substance in a compound/mixture divided by the total number of substances in the same compound or mixture.

In this case, we can say that mole fraction represents the number of solutes to the number of solutes and solvent in the solution i.e. X = nA/nA + nB

Where; nA = number of solutes

nB = number of solvent

X = mole fraction.

Based on this analogy, When the mole fraction of solute is 1, there is only solute present. That is; X = 1 / 1 + 0

X = 1/1 = 1.

Answer:

12 cm³

Explanation:

Always round to the place of the number with the least amount of significant figures.

1.74 and 3.09 have three significant figures. 2.3 has two significant figures. Therefore, the answer will be rounded to two significant figures.

1.74 cm × 2.3 cm × 3.09 cm = 12.36618 -> 12 cm³

(The 3 in the tenths place is less than 5 so drop it and all the numbers to the right of it.)

Hope that helps.

Answer:

I'm not sure but I think the answer is electrons, protons and neutrons.

Answer:

Percent yield = 99.6%

Theoretical yield = 25.5 g

Explanation:

Given data:

Mass of copper = 12.5 g

Mass of copper(II) chloride produced = 25.4 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

Cu + Cl₂       →        CuCl₂

Number of moles of copper:

Number of moles = mass/molar mass

Number of moles = 12.5 g / 63.5 g/mol

Number of moles = 0.19 mol

Now we will compare the moles of copper and copper chloride.

                  Cu          :           CuCl₂

                     1           :               1

                  0.19        :           0.19

Mass of CuCl₂: Theoretical yield

Mass = number of moles × molar mass

Mass = 0.19 mol × 134.45 g/mol

Mass = 25.5 g

Percent yield:

Percent yield = (actual yield / theoretical yield )×100

Percent yield  = ( 25.4 g/ 25.5 g) ×100

Percent yield = 99.6%

Answer:b

Explanation:

Answer:

16 g/mol

Explanation:

In CO2, it means we have 1 mole of carbon and 2 moles of oxygen.

However, we want to find the molar mass of just a single mole of oxygen.

Now, from tables of values of elements in electronic configuration, the molar mass of oxygen is usually approximately 16 g/mol.

In essence the molar mass is simply the atomic mass in g/mol

Answer: Gold.

Explanation: Water, CO2, and table salt are compounds. They are composed of two or more separate elements; a mixture, where as gold is neither.

Answer:

For a cat name does matter as it keeps a charm when ever we call the name out. So it needs to be cherished as by a name so if it was me i would name it as Chinky.

Answer:

Chemical laws are those laws of nature relevant to chemistry. The most fundamental concept in chemistry is the law of conservation of mass, which states that there is no detectable change in the quantity of matter during an ordinary chemical reaction. Modern physics shows that it is actually energy that is conserved, and that energy and mass are related; a concept which becomes important in nuclear chemistry. Conservation of energy leads to the important concepts of equilibrium, thermodynamics, and kinetics.

Explanation:

Have A Wonderful Day !!

Answer:

Chemical laws are those laws of nature relevant to chemistry. ... The laws of stoichiometry, that is, the gravimetric proportions by which chemical elements participate in chemical reactions, elaborate on the law of conservation of mass.

Explanation:

Answer:

d = 8.96 g/cm³

Explanation:

Given data:

Volume of sample = 10.0 cm³

Mass of copper = 89.6 g

Density of copper = ?

Solution:

Formula:

d = m/v

d = density

m = mass

v = volume

by putting values,

d = 89.6 g/ 10.0 cm³

d = 8.96 g/cm³

Answer:

Density, d = 8.92 g/mL

Explanation:

Let mass of the wooden block, m = 46.83  g

The volume of the object, V = 5.25 mL

We need to find the density of the wooden block. The density of an object is given by its mass per unit volume.

density = mass/volume

[tex]d=\dfrac{46.83\ g}{5.25\ mL}\\\\=8.92\ g/mL[/tex]

So, the density of the wooden block is 8.92 g/mL.

Answer:

0.495 g/cm3

Explanation:

Answer:

protozoan

Explanation:

An animal - like unicellular protist is called a protozoan. Such organisms shows similarities with animals.

Answer:

To be stable, an atom or ion should have 8 electrons in the outer shell. This is called the octet rule.

Magnesium is unstable because a magnesium atom has 2 valance electrons in its 3rd shell.

Chlorine is unstable, because a chlorine atom has 7 valance electrons is its 3rd shell.

Chlorine has higher electronegativity than magnesium, so the 2 chlorine atoms will attract 2 electrons from a magnesium atom. This produces a +2 magnesium ion and two -1 chloride ions.

A) A Cl atom donates two electrons to a Mg atom  

B) An Mg atom donates two electrons to a Cl atom.  

C) A Cl atom donates one electron to each of the two Mg atoms.  

D) An Mg atom donates one electron to each of the two Cl atoms. YES

Atoms do not donate any electrons. When a chlorine molecule collides with a magnesium atom, each of the chlorine atoms grab an electron from the outer shell of the magnesium atom. You might think that the magnesium atom would be angry at the chlorine molecule. But, the magnesium atom is much “happier” as a stable +2 ion than a neutral atom. And the chlorine molecule is also “happier” as two -1 chloride ions.

Magnesium chloride is the name for the chemical compounds with the formulas MgCl2 and its various hydrates MgCl2(H2O)x. These salts are typical ionic halides, being highly soluble in water. The hydrated magnesium chloride can be extracted from brine or sea water. Magnesium chloride as the natural mineral bischofite is also extracted (solution mining) out of ancient seabeds; for example, the Zechstein seabed in northwest Europe. Anhydrous magnesium chloride is the principal precursor to magnesium metal, which is produced on a large scale. Hydrated magnesium chloride is the form usually used in prescription oral magnesium supplements.

We are the ones who messed with mother nature. Magnesium chloride was very stable (happy) when it was in the sea water. Humans decided to harvest the MgCl2 and rip it apart to produce little strips of magnesium metal for chemistry class.

In nature, “nobody” freely donates anything to “anyone”. The electrostatic forces in the atoms decide who get the electons.

Sometimes, I just get carried away as I answer peoples’ question.

I hope this helped you.

Answer:

Percentage of O = 56.1 %

Percentage of Al =15.8%

Percentage of S = 28.1 %

Explanation:

Given compound Al₂(SO₄)₃

Molar mass of compound:

27×2 + 32×3 + 16×12 = 342 g/mol

Percentage of Al = ( Mass of Al / Total mass ) × 100

Percentage of Al = 54 /342 × 100

Percentage of Al =15.8%

Percentage of S = ( Mass of S / Total mass ) × 100

Percentage of S = 96 /342 × 100

Percentage of S = 28.1 %

Percentage of O = ( Mass of O / Total mass ) × 100

Percentage of O = 192 /342 × 100

Percentage of O = 56.1 %

Answer:just for the ponits

Explanation:ima be a jenna

Answer:

Most erosion is performed by liquid water, wind, or ice (usually in the form of a glacier). If the wind is dusty, or water or glacial ice is muddy, erosion is taking place. The brown color indicates that bits of rock and soil are suspended in the fluid (air or water) and being transported from one place to another. This transported material is called sediment.

Explanation:

we are lerning this tooo

Answer: There are [tex]10.5\times 10^{23}[/tex] formula units in 1.75 mol sample of NaCl.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

1 mole of NaCl contains = [tex]6.023\times 10^{23}[/tex] formula units

Thus 1.75 mol of NaCl contains = [tex]\frac{6.023\times 10^{23}}{1}\times 1.75=10.5\times 10^{23}[/tex] formula units

Thus there are [tex]10.5\times 10^{23}[/tex] formula units in 1.75 mol sample of NaCl.

Answer:

C. H2(g)

Explanation:

Answer:

I believe it’s the mitochondria

Explanation:

Answer:

Mitochondria

Explanation:

Ik bc i have the vocab for that question

Answer:

332g

Explanation:

Given parameters:

Formula units  = 2 x 10²⁴

Unknown:

Mass of the compound = ?

Solution:

The formula of the compound is:

            CaCO₃

      6.02 x 10²³ atoms are contained in 1 mole of a compound

       2 x 10²⁴ atoms will be made up of [tex]\frac{2 x 10^{24} }{6.02 x 10^{23} }[/tex]   = 3.32mole of CaCO₃

 Mass of CaCO₃  = number of moles x molar mass

      Molar mass of CaCO₃  = 40 + 12 + 3(16) = 100g/mol

 Mass of CaCO₃  = 3.32 x 100  = 332g

Answer:

B. Isotopes mean having differing number of neutrons but having the same amount of protons basically.

Explanation:

B. The atoms are isotopes of each other

Given

The first atom : 8 protons, 8 neutrons and 8 electrons

The second atom : 8 protons, 10 neutrons and 10 electrons

Required

Comparison

Solution

A. Atom is said to be neutral if the number of protons and electrons is the same

The first atom neutral

The second atom - anion : charge = -2(10 electron-8 proton)

B. isotopes = the same atomic number and different mass number

The first atom : atomic number = 8, mass number = 16

The second atom neutral : atomic number = 8, mass number = 18

Both : isotopes

C. First atom = neutral, second atom anion (charge = -2)

D. Can exist in nature

Answer:

yes

explanation:

yes because when the velocity is low, all the energy is low and nothing can't do nothing without energy

Answer:

1.00 g

Explanation:

got it on pex

Answer:

to collect liquid ethanol and leave ethene as a gas because ethanol has hydrogen bonds    

Explanation:

The chemist would be lesser than the temperature of the mixture as to collect the liquid ethanol and then leave ethene as a gas since the ethanol is a bond that should be hydrogen. Also -OH that available in the ethanol would be responsible for the hydrogen bonds also it is the main and significant molecular forice

So as per the given situation the above represent the answer

Answer:

to collect liquid ethanol and leave ethene as a gas because ethanol has hydrogen bonds    

Explanation:

Answer:

Household cleaners, antiseptics and battery juice are examples of toxic chemicals that you cannot consume because they have high acids concentrations. However some are very healthy such as critic acids found in oranges. :) Hope this helped.

Answer:

0.01M = [H⁺]; 1x10⁻¹²M = [OH⁻]; Ratio is: 1x10¹⁰

Explanation:

pH is defined as -log [H⁺]

For a pH of 2 we can solve [H⁺] as follows:

pH = -log [H⁺]

2 = -log [H⁺]

10^-2 = [H⁺]

Using Keq of water:

Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]

1x10⁻¹⁴ / 0.01M = [OH⁻]

The ratio is:

[H⁺] / [OH⁻] = 0.01 / 1x10⁻¹² =

Answer:

1. 0.01 mol/L

2. 0.000000000001 mol/L

3. 10000000000:1

Explanation: