Answer:
13.4 (w/w)% of CaCl₂ in the mixture
Explanation:
All the Cl⁻ that comes from CaCl₂ (Calcium chloride) will be precipitate in presence of AgNO₃ as AgCl.
To solve this problem we must find the moles of AgCl = Moles of Cl⁻. As 2 moles of Cl⁻ are in 1 mole of CaCl₂ we can find the moles of CaCl₂ and its mass in order to find mass percent of calcium chloride in the original mixture.
Moles AgCl - Molar mass: 143.32g/mol -:
0.535g * (1mol / 143.32g) = 3.733x10⁻³ moles AgCl = Moles Cl⁻
Moles CaCl₂:
3.733x10⁻³ moles Cl⁻ * (1mol CaCl₂ / 2mol Cl⁻) = 1.866x10⁻³ moles CaCl₂
Mass CaCl₂ -Molar mass: 110.98g/mol-:
1.866x10⁻³ moles CaCl₂ * (110.98g/mol) = 0.207g of CaCl₂ in the mixture
That means mass percent of CaCl₂ is:
0.207g CaCl₂ / 1.55g * 100 =
13.4 (w/w)% of CaCl₂ in the mixtureStoichiometry
1. Based on the equation, Mg+2NaF => MgF2 + 2Na , if 23.56 grams of magnesium reacts with sufficient sodium
fluoride, how many grams of sodium will be produced?
Since we have sufficient sodium fluoride (NaF), the magnesium (Mg) will be our limiting reactant, and we will use its coefficient in the balanced equation to determine our molar ratio between the product of interest which, in this case, is sodium (Na).
We are given the mass of magnesium, 23.56 grams, which we must convert to moles by dividing the mass by the molar mass of magnesium: (23.56 g)/(24.305 g/mol) = 0.9693 mol Mg.
According to the balanced equation given, the molar ratio between sodium and magnesium is 2:1. That is, for every 2 moles of Na that are produced, one mole of Mg is consumed or reacted. The upshot is that the number of moles of sodium produced will be double the number of moles of Mg reacted. Since we have 0.9693 moles of Mg available to react, we will obtain (0.9693 mol Mg)(2 mol Na/1 mol Mg) = 1.939 mol Na.
Finally, we multiply our moles of sodium by the molar mass of sodium to get the mass: (1.939 mol Na)(22.99 g/mol) = 44.57 grams Na.
So, 44.57 grams of sodium will be produced.
The answer is given to four significant figures.
The decay of radioactive elements occurs at a fixed rate. The half-life of a radioisotope is the time required for one half of the amount of unstable material to degrade into a more stable material. The half-life of Carbon-14 is 5,730 years. Choose ALL the true statements regarding the Carbon-14 isotope. A) 100 grams of C-14 decays to 25 grams in 11,460 years. B) The C-14 isotope is only useful for dating fossils up to about 50,000 years old. C) A sample contained 3,360 atoms of C-14. 8 half-lives passed and 210 C-14 atoms remained. D) If an ancient bone contains 6.25% of its original carbon, then the bone must be 22,920 years old. E) A sample of 4,000 radioactive C-14 atoms undergoes decay. After 5 half-lives there are 800 radioactive atoms remaining.
Answer:
100 grams of C-14 decays to 25 grams in 11,460 years.
The C-14 isotope is only useful for dating fossils up to about 50,000 years old
If an ancient bone contains 6.25% of its original carbon, then the bone must be 22,920 years old.
Explanation:
We already know that the half life of C-14 is 5,730 years. After the first half life, we have 50 grams remaining. This takes 5,730 years. After the second half life (11,460 years now gone) we have 25 grams of C-14 left.
If a fossil material is older than 50,000 years an undetectable amount of 14C is left in the sample hence Carbon-14 is no longer suitable for dating the sample.
From;
0.693/5730 = 2.303/t log (No/0.0625No)
Where;
t = time taken and No = initial amount of C-14
0.693/5730= 2.77/t
t = 22,920 years
Which of the following is another term for eruptions of gas on the sun's surface?
A. nuclear fusion
B. sunspots
C. coronas
D. solar flares
Answer:
D
Explanation:
I NEED HELP THIS IS DUE TMR!
A 124.6-g sample of copper has a volume of 14 cm. what is the density of copper?
Answer:
The density of copper is 8.9 grams per cubic centimeter.
Explanation:
There is a writing mistake in statement, correct form is written below:
A 124.6 grams sample of copper has a volume of 14 cubic centimeters. What is the density of copper?
Let suppose that mass of the copper sample is distributed uniformly in its volume, then we shall use the following definition of density ([tex]\rho[/tex]), in grams per cubic centimeter:
[tex]\rho = \frac{m}{V}[/tex] (1)
Where:
[tex]m[/tex] - Mass, in grams.
[tex]V[/tex] - Volume, in cubic centimeters.
If we know that [tex]m = 124.6\,g[/tex] and [tex]V = 14\,cm^{3}[/tex], then the density of the sample of copper is:
[tex]\rho = \frac{m}{V}[/tex]
[tex]\rho = 8.9\,\frac{g}{cm^{3}}[/tex]
The density of copper is 8.9 grams per cubic centimeter.
9. Which of the following would increase the
validity of Experiment 2?
A. Testing magnets with a volume less
than 0.04
B. Testing magnets made of iron instead
of ceramic
C. Testing generators with larger
vibrations
D. Testing a generator with coils fewer
than 2050
.
What happens to the amount of carbon dioxide as the population increases?
Answer:
when population increases the amount of carbon dioxide also increases as population use oxygen and release carbon dioxide
Carbon dioxide is a major greenhouse gas. The increase in the population increases the carbon dioxide amount.
What is the relation between carbon and population?The main product released from the respiratory process of organisms, especially animals is carbon dioxide. The increase in their population will increase this product.
The increased population will increase the demand for the burning of fossil fuel, pollution, and respiration, and hence the product of these activities, carbon dioxide will increase in the atmosphere.
Therefore, the carbon dioxide will increase with an increase in the population.
Learn more about carbon dioxide and population here:
https://brainly.com/question/10153143
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Is combining ammonium chloride and water a physical or chemical change
why should atom or ions join together to form compounds?
Answer:
while atoms form together, they percentage their outermost electrons to create more sustainable strength states. This sharing bonds the atoms into an ionic shape or a molecule
Explanation:
i hope this help a little
What is the relationship between the valence electrons of an atom and the chemical bonds the atom can form?
Answer:
Valence electrons are outer shell electrons with an atom and can participate in the formation of chemical bonds. In single covalent bonds, typically both atoms in the bond contribute one valence electron in order to form a shared pair. The ground state of an atom is the lowest energy state of the atom.
Calculate the molar mass of a solute in a 1.30 L solution with of 0.50 M
containing 10.5 g of the solute.
Answer: 16 g/mol
Explanation: Molarity is Moles/Liters or Mol/L
(0.50 mol/L)(1.30L) = 0.65mol
(cancels out L)
Molar mass is g/mol so...
10.5g/0.65mol = 16.1 g/mol
Rounded to 2 sig figs is 16 g/mol
explain why it is important to eat the wet sand before heating the iron wool
Answer:
huh,eat wet sand b4heating iron wool??
What types of elements [metals/nonmetals] are found in each of the compounds?
Not a simple answer please
Explanation:
List of All Elements That Are Nonmetals
Hydrogen (sometimes)
Carbon.
Nitrogen.
Oxygen.
Phosphorus.
Sulfur.
Metals:-
Gold.
Silver.
Iron.
Copper.
Nickel.
Aluminum.
Mercury( Liquid metal)
Titanium.
Fluorine.
20 POINTS: Why it's important for science fair participants to not only create an informative and attractive presentation, but also to detail their information, ideas, and research in a science report.
Answer:
To show what they know!
Explanation:
If you're not showing how you did your experiment thoroughly, then nobody will understand what you did! For instance, if you spent 2 weeks studying really hard about how music affects different kinds of animals, and only put down that music affects animals and no showing your work. Then no one will know how much effort and work you put into it! If you put all the minor details into the presentation, then more than likely everyone will know where your coming from!
Hope this helps! Plz mark as brainliest!
why an indicator is a necessary part of the titration experiment?
Answer:
In a titration, you determine an unknown concentration of a sample by adding a second reactant of known concentration. In many titrations, you use a chemical called an indicator, which lets you know when the titration finishes.
Explanation:
what is the difinition of the word democracy?
Answer:
Democracy/dɪˈmɒkrəsi/
--noun--
A system of government by the whole population or all the eligible members of a state, typically through elected representatives.
If five gases in a cylinder EACH exert a partial pressure of 2.5 atm, what is the total pressure in the cylinder? Be sure to bubble your answer on the answer sheet.
Answer:
16 atm
Explanation:
Uma peça de metal de formato irregular feita de uma liga particular foi galvanizada com zinco usando uma solução de Zn(NO₃)₂. Quando uma corrente de 2,70 A foi usada, levou exatamente 1 hora para depositar uma camada de 0,015 mm de zinco na peça. Qual é a área total de superfície da peça? A densidade do zinco é de 7,14 g /cm³. Suponha que a eficiência seja 100%. MM (Zn) = 65,4 g/mol; 1 mol e = 96500 C.
What is the number of moles in 15.0 g AsH3?
O 5.2 mol
O 1200 mol
O 0.44 mol
O 0.19 mol
Answer:
n = 0.19 mol
Explanation:
Given mass = 15 g
The molar mass of AsH₃ = 77.94 g/mol
We need to find the number of moles in 15 g of AsH₃. We know that,
No. of moles = given mass/molar mass
[tex]n=\dfrac{15}{77.94 }\\\\n=0.19\ mol[/tex]
So, there are 0.19 g/mol. Hence, the correct option is equal to 0.19 mol.
What is the Ka of a 0.0981 M
solution of hydrocyanic acid
(HCN) with a pH of 6.00?
Ka = [?] x 10!?)
Answer:
Attached picture
Ka = [?] x 10
1.02 x 10^-11 = [?] x 10
[?] = 1.02 (I'm assuming you're asking this)
(If not then divide the 10)
Answer:
The answer is 1.02x10^-11
Explanation:
Fill in the box 1.02 and then -11
Which of the following pictures is a chemical change, and which is a
physical change? Explain in the boxes next to the picture.
Plz explain
Answer:
left is chemical because its chemicals, and right is physical because the ice cream is melting and thats physical
Explanation:
Which boundary or zone adds new material to the lithosphere (the hard outer crust of the Earth)
Answer:Divergent Boundaries(or Boundary)
Explanation:took the test and got it right
Mass number symbol =
Answer:
A is the symbol of mass number.
Explanation:
→ Mass number (A) = Protons + Neutrons
It is the required formula. The symbol of the mass number is A.
Answer:
The letter A
Explanation:
HELP PLEASE!!!!!!!!!!!!
Answer:
it is a practical question..ASAP
7. Which of the following physical changes is experienced by women during the luteal stage of the
menstrual cycle?
a. Mood swings b. Changes in appetite c. Depression or sadness d. Headaches or
backaches
Answer:
The correct answer is Choice D.
(Headaches or backaches)
Explanation:
Hope this helps!
Please mark me as Brainlinieast.
how to obtain pure aluminium oxide from sodium aluminate. pls help.
Answer:
By Bayer process.
Explanation:
In the Bayer process, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution (caustic soda) at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as sodium aluminate (primarily [Al(OH)4]−) in an extraction process.
On a summer day in Breckenridge, Colorado, the atmospheric pressure is 525 mm Hg. What is this air pressure in West Chester, Pennsylvania as it relates to the pressure in Colorado?
a. The same as in Colorado
b. Lower than in Colorado
c. Higher than in Colorado
d. There is not enough information to tell.
Answer:
Option B
Explanation:
The atmospheric pressure in West Chester, Pennsylvania is lower than the pressure on any summer day in Breckenridge, Colorado
Colorado is 1.6 kilometers above sea level while Pennsylvania is 0.33 kilometers above sea level.
The higher a place is above sea level, the higher is the air pressure.
Hence, option B is correct
Question 1 (1 point) How many stars are in our solar system? A. About 20.000 B. About 300,000 C. One D. About 5,000
Answer:
C. one star
Explanation:
Of course our solar system has one unique star which is the sun while others have atleast two which are called binary solar
Which is the term for the different forms of a gene for a given trait?
Answer:
An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.
calculate the molecular mass of N2O3
the answer is 76.01g/mol
and the density:1.4g/cm³
Determinar el volumen de una solución en mililitros cuya concentración es 0,3 M en ácido sulfúrico y que contiene 1,5 moles del ácido
Answer:
V = 5000 mL
Explanation:
¡Hola!
En este caso, dado que la molaridad de una solution se calcula al dividir las moles por el volume de solución en litros, es posible calcular el volumen cuando se dividen las moles por la molaridad, tal y como se muestra a continuación:
[tex]M=\frac{n}{V}\\\\V=\frac{n}{M}[/tex]
Así, podemos reemplazar la molaridad y moles dadas para obtener:
[tex]V=\frac{1.5mol}{0.3mol/L}=5L[/tex]
Que en mililitros sería:
[tex]V=5L*\frac{1000mL}{1L}\\\\V=5000mL[/tex]
¡Saludos!