0.50 mol SiO₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
30 g SiO₂ (sand)
Step 2: Identify Conversions
Molar Mass of Si - 28.09 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of SiO₂ - 28.09 + 2(16.00) = 60.09 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 30 \ g \ SiO_2(\frac{1 \ mol \ SiO_2}{60.09 \ g \ SiO_2})[/tex]Multiply/Divide: [tex]\displaystyle 0.499251 \ mol \ SiO_2[/tex]Step 4: Check
Follow sig figs and round. We are given 2 sig figs.
0.499251 mol SiO₂ ≈ 0.50 mol SiO₂
Answer:
[tex]\boxed {\boxed {\sf About \ 0.5 \ moles \ of \ SiO_2}}[/tex]
Explanation:
To convert from grams to moles, we must use the molar mass.
1. Molar Mass
Use the Periodic Table to find the masses of the individual elements (silicon and oxygen) in sand.
Silicon (Si): 28.085 g/mol Oxygen (O): 15.999 g/molExamine the formula for sand: SiO₂. There is a subscript of 2 after oxygen, so there must be 2 oxygen atoms. Multiply oxygen's mass by 2 and add silicon's mass to find the molar mass of sand.
SiO₂: 2(15.999 g/mol) + 28.085 g/mol= g/mol2. Calculate Moles
Use the molar mass as ratio.
[tex]\frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]
Multiply by the given number of grams (30)
[tex]30 \ g \ SiO_2 * \frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]
Flip the fraction so the grams of sand will cancel.
[tex]30 \ g \ SiO_2 *\frac{1 \ mol \ SiO_2}{60.083 \ g \ SiO_2}[/tex]
[tex]30 *\frac{1 \ mol \ SiO_2}{60.083 }[/tex]
[tex]\frac{30 \ mol \ SiO_2}{60.083 }[/tex]
[tex]0.499309289 \ mol \ SiO_2[/tex]
3. Round
The original measurement of grams has 1 signfiicant figure. We must round our answer to 1 sig fig.
For the answer we found, that is the tenth place. The 9 in the hundredth tells us to round the 4 to a 5.
[tex]\approx 0.5 \ mol \ SiO_2[/tex]
There are about 0.5 moles of SiO₂ in 30 grams.
Question 6
Use the mole concept to calculate the number of formula units that are in a 1.75-mol sample of NaCl.
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.
Which of the following is NOT a compound?
Table salt
Carbon dioxide
Water
Gold
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.
4. When the mole fraction of solute is 1, there is
(a) a 1:1 ratio of solute to solvent.
(b) no solute present.
(c) only solute present.
(d) only solvent present.
(e) 1 mole of solute and 99 moles of solvent.
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.
Density is defined by the equation d = m/v. Calculate the density of the wooden block, the rock, and the water by dividing the mass of each object by its volume.
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:
what is the molar mass of just the O in CO2?
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
7. A 10.0 cm3 sample of copper has a mass of 89.6 g. What is the density of copper?
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
Which combination of elements produce compounds with a large electronegativity difference and high conductivity?
Answer:
C. H2(g)
Explanation:
How many liters of 3^He are present in 22 moles of gas?
3. If 12.5 grams of copper are reacted with excess chlorine gas, then 25.4 grams of
copper (II) chloride are produced. Calculate the theoretical yield and the percent
yield. Cu + Cl2 → CuCl2
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%
What is the concentration of H+ ions at a pH = 2?
mol/L
What is the concentration of OH– ions at a pH = 2?
mol/L
What is the ratio of H+ ions to OH– ions at a pH = 2?
: 1
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⁺]
0.01M = [H⁺]Using Keq of water:
Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]
1x10⁻¹⁴ / 0.01M = [OH⁻]
1x10⁻¹²M = [OH⁻]The ratio is:
[H⁺] / [OH⁻] = 0.01 / 1x10⁻¹² =
1x10¹⁰Answer:
1. 0.01 mol/L
2. 0.000000000001 mol/L
3. 10000000000:1
Explanation:
What is an animal-like, unicellular protist called?
protozoan
euglenoid
slime mold
decompos
Answer:
protozoan
Explanation:
An animal - like unicellular protist is called a protozoan. Such organisms shows similarities with animals.
Protozoans are unicellular organisms. They are similar to animals in that they perform nearly all life functions that makes animals very unique. They are mostly heterotrophs which feed on foods that have been produced by autotrophs. Examples are flagellates and ciliates.how many mercury atoms are contained in 0.37 moles of mercury?
pick repel,or attract. were its circled
Thomas calculates the volume of an object by multiplying the measurements 1.74 cm x 2.3 cm x 3.09 cm. Using significant figures, how should the answer be reported?
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.
Complete the graphic organizer.
Basic Parts of an Atom
Answer:
I'm not sure but I think the answer is electrons, protons and neutrons.
How many grams are in 2x10^24 formula Units of CaCO3
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
D. The ¬_____________________ converts food into energy. It is found in both plant cells and animal cells.
Answer:
I believe it’s the mitochondria
Explanation:
Answer:
Mitochondria
Explanation:
Ik bc i have the vocab for that question
Will get brainliest.
Answer:
1.00 g
Explanation:
got it on pex
Does it take shorter or longer time to travel when the velocity is low?
Answer:
yes
explanation:
yes because when the velocity is low, all the energy is low and nothing can't do nothing without energy
What is the chemical law?
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:
please help!! I’m really confused because it’s actually supposed to be called occluded front but the definition is true.
Number 2 & 3 please !!<3
Answer:just for the ponits
Explanation:ima be a jenna
The yard cat above is named "Yardley" for reasons obvious to his owner.
Yardley spends most of his time lounging in the back yard chasing
carpenter bees. But he could have been given any number of names
based on his appearance or behavior. Think for a few minutes. What
would you name him if he were your cat?
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.
Which Atom experiences a greater shielding effect, Magnesium (Mg) or chlorine (CI)?
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.
Describe how wind, water, ice and gravity move soil through erosion below.
PLEASE ANSWER!!!! :D
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
according to the Aufbau principle, which principle energy level would have higher energy, n=2 or n=5?
Answer:b
Explanation:
An atom contains 8 protons, 8 neutrons and 8 electrons. A second atom contains
8 protons, 10 neutrons and 10 electrons. What can be said about these two
atoms?
A. Both atoms are neutral
B. The atoms are isotopes of each other
C. Both atoms are ions
D. These atoms cannot exist in nature
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
Further explanationGiven
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
When chemists convert ethene (C2H2) to ethanol (CH3CH2OH), they have a mixture of the two gaseous substances. Why do chemists then lower the temperature of the mixture?
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:
Calculate the percentage composition of Aluminum, Sulfur & Oxygen in the compound of Al(SO4)3
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 %
4 Explain why some acids are safe to consume
while others are not.
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.