The percentage by mass of Na2CO3 in the sample is 48%.
The equation of the reaction of Na2CO3 with HCl;
Na2CO3(aq) + 2HCl(aq) ------> 2NaCl(aq) + H2O(l) + CO2(g)
Since the HCl is in excess, the excess is back titrated with NaOH as follows;
NaOH (aq) + HCl(aq) ---->NaCl(aq) + H2O(l)
Number of moles of HCl added = 0.100 M × 50/1000 L = 0.005 moles
Number of moles of NaOH added = 5.6/1000 × 0.100 M = 0.00056 moles
Since the reaction of NaOH and NaOH is 1:1, 0.00056 moles of HCl reacted with excess HCl.
Amount of HCl that reacted with Na2CO3 = 0.005 moles - 0.00056 moles = 0.0044 moles
Now;
1 mole of Na2CO3 reacts with 2 moles of HCl
x moles of Na2CO3 reacts with 0.0044 moles of HCl
x = 1 mole × 0.0044 moles / 2 moles
x = 0.0022 moles
Mass of Na2CO3 reacted = 0.0022 moles × 106 g/mol = 0.24 g
Percentage of Na2CO3 in the sample = 0.24 g/ 0.500-g × 100/1 = 48%
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Can someone help? Thank you.
that' the answer i don't need an explanation
Polyvalent ions are
1) Anions with variable charges
2) Cations from columns 3 to 12
3) Ions that can be positive or negative
What is the mass of an aluminum block if the density of aluminum is 2.70
g/cm and the volume of that block is 4.8 cm?
Answer: 50 M
Explanation:
Mass
Density×Volume2.7(4.8)11.6111.6gFormula used
Density=Mass/VolumeSulfuric acid reacts with sodium carbonate to form water, a salt, and a gas. Write the formulas for the salt and other compound that are formed in the reaction.
Answer:
H2So4 + Na2Co3 -> H20 + Na2So4 + CO2
The chemical formulas for the salt and other compound that are formed in the reaction are Na₂SO₄,H₂O and CO₂.
What is chemical formula?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
There are four types of chemical formula:
1)empirical formula
2) structural formula
3)condensed formula
4)molecular formula
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Which of the following is not part of an amino acid?
A. ammonium group
B. carboxylate group
C. ether group
D. unique "R" group
Answer:
C
Explanation:
Ether group does not exist in amino acids
Ammonium group is on one side
the carboxylate group is opposite to the ammonium group
the R group defines what amino acid it is.
what are the solar home lighting
Answer:
Sunlight
Explanation:
Home lighting System is powered by solar energy using solar cells that convert solar energy (sunlight) directly to electricity. The electricity is stored in batteries and used for the purpose of lighting whenever required
Which pair of elements form an ionic bond with
each other?
A. KCL
B. ICL
C. PCL
D. HCL
I think it’s A and D but if it’s not both can you please explain why it’s one and not the other?
Answer:
Yes Both A) KCL and D) HCL are correct...
Answer:
It's only A
Explanation:
Potassium (K) is a metal and Chlorine (Cl) is a nonmetal, and ionic compounds are formed between metals and nonmetals. So KCl forms ionic bonds.
Hydrogen (H) and Chlorine (Cl) are both nonmetals, and only covalent bonds form between nonmetals. (Only exception is when its an acid, then it's ionic)
Also, the question indicated which "pair" and not "pairs" meaning that there is only one answer, and I'm more likely to go with A rather than D.
Describe echolocation. Give an example of an animal that uses echolocation.
dolphin and whales use echolocation
Would you expect a Boron (B) atom with atomic mass = 9.999 to be stable?
The balance of forces allows to find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 uma is unstable because the repulsive force increases.The stability of atomic nuclei depends on the balance the force is electrostatic repulsion between the protons and the strong interaction of attraction.
One way to achieve this balance is to increase the separation of the protons with uncharged particles between them, the neutral ones, the strong interaction is of the same magnitude for protons and neutrons, therefore the repulsion is decreased and the strong attraction interaction is maintained. .
In the case of Boron, which has 5 protons, the stable structures have more atomistic 10 and 11 una, which is why it has 5 and 6 neutrons each. Therefore each proton has a neutrons next to it and in the other case a proton at the end has two neutrons, this causes the distance between the protons to increase, decreasing the electrostatic repulsion.
It indicates that we have a Boron nucleus of mass 9.999. The number of protons must remain fixed, therefore there are only 4 neutrons.
Consequently, some of the protons does not have a neutron next to it and can approach the other proton, therefore the electrostatic repulsion increases and the stability of the atom decreases.
In conclusion, using the balance of Forces we can find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 amu is unstable because the repulsive force increases.Learn more about nuclear stability here: https://brainly.com/question/897383
50 PTS!!!!!
What type of chemical reaction is Aerobic Cellular Respiration?
Answer: During aerobic respiration, catabolic reactions convert larger complex organic molecules into ATP, the chemical that drives most physiological processes in the body.
Explanation:
increasing temperature increases:
1:Enthalpy
2:Free Energy
3:Entropy
4:Specific heat
Answer:
2 :free energy
Explanation:
I hope it is fine answer for you ☺️☺️☺️
Diazene, N2H2 (also known as diimine), is commonly used as a reagent for organic syntheses. Label each image with the type of
bond in diazene that it shows.
The first image shown at the left hand side is a pi bond. The other two images show sigma bonds.
In chemistry, a bond results from the overlap of atomic orbitals. This overlap may be end to end (sigma bond) or side by side (pi bond). Having said this, it is easier to decide whether the bonds in the image shown are sigma or bi bonds.
If we label the images; 1,2,3 from left to right, we can see that the overlap in image 1 is side by side. The electron density lies above and below the plane of the bond. This is a pi bond. In images 2 and 3, the overlap occurs in an end to end manner. This is a sigma bond.
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what is the chemistry of super glue
cyanoacrylate
When cyanoacrylate polymerizes, the cyanoacrylate sticks together on an atomic level, and it becomes solid. Super Glue solidifies in all the microscopic crevices of an object that it moved into when it was a liquid, and it can form chemical bonds with any anions in the object.
which planet is closests to the moon
Answer:
Earth
Explanation:
Answer:
Earth
Explanation:
Hope this helps! Pls give brainliest! Also, please sub to Kgirl633 on yt.
how do you Calculate the molarity of 250 ml of solution in which 2.7 g of MgCl2 are dissolved
Answer:
Molar mass of MgCl2 is 95 g/mol
Mg = 24 g/mol and Cl = 35.5 ×2 = 71 g/mol
moles = mass given/ molar mass
= 2.7/95 = 0.028 mol
volume = 250/1000 = 0.25 dm3 (ml is the same as dm3)
molarity of MgCl2 = moles/volume
= 0.028/0.25
= 0.112 mol/dm3
What is the total pressure exerted by a mixture containing two gases if the partial pressure of one gas is 70 kPa and the partial pressure of the other gas is 30 kPa?
Answer:
The total pressure of a mixture of gases can be defined as the sum of the pressures of each individual gas: Ptotal=P1+P2+… +Pn. + P n . The partial pressure of an individual gas is equal to the total pressure multiplied by the mole fraction of that gas.
Explanation:
hope this helps have a wonderfull day!
Define Endothermic reaction in terms of Deta H
I didn't learn about that topic in school,but I found this :
I hope it helps<3
Why does the Hubble Space Telescope take clearer pictures than other telescopes?
Answer:
Space-based telescopes like Hubble get a much clearer view of the universe than most of their ground-based counterparts. ... Ground-based telescopes can't do the same, because the Earth's atmosphere absorbs a lot of the infrared and ultraviolet light that passes through it.
how many compounds can I make with sodium, hydrogen, oxygen?
will give brainliest and 100 points to the correct answer
Answer:
маны
Explanation:
Answer:
2H2 + O2 → 2H2O
Explanation:
As an electron in an atom moves from a higher energy state to a lower energy state, the atom
A
becomes a negative ion
В.
becomes a positive ion
С.
releases energy
D.
absorbs energy
Answer:B
Explanation:
Which of the following is a challenge of prosthetic engineering that has been met through tissue engineering?
- Predicting failure
- Biocompatibility
- Strength
- Power
Answer:
Biocompatibility
Explanation:
I’m a genius and it’s the answer :D
Biocompatibility is a challenge of prosthetic engineering that has been met through tissue engineering. Hence, option B is correct.
What is Biocompatibility?Biocompatible materials are used in medical devices, such as menstrual cups, stents, or ventilators.
A biocompatibility problem might happen when some of the materials are trapped in the patient's gingival sulcus.
Tissue engineering is an important field of regenerative medicine for tissue repair (after damaged caused by a disease or an accident, for example).
To offer this possibility, stem cells are important tools owing to their capacity to differentiate into a large number of cells according to the stimuli provided.
Hence, option B is correct.
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If 2.5 moles of PA react completely, how many
moles of P203 are formed?
Answer:
For every 2 moles of Na used, 2 moles of NaCl are produced.
Explanation:
To calculate the atomic mass of an element, the percent
abundance of etch isotope is needed. ?
Answer:
List the known and unknown quantities and plan the problem. Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass
Explanation:
It takes 120 mL of 0.15 M of carbonic acid (H2CO3) to neutralize 300 mL of sodium hydroxide (NaOH) for the following balanced chemical reaction:
2NaOH + H2CO3 → N2CO3 + 2NaOH
The concentration of the sodium hydroxide _____.
Which of the following best represents a chemical change?
A. Chopping wood
B. Silver tarnishing (changing color)
C. Grape kool-aid mix dissolving in water
D. Dry ice turning into a gas (sublimation- a change of state)
B. silver tarnishing
calculate the mass percentage of each element in aluminum oxide.Then calculate themass of aluminum in a 3.62 gram sample of of aluminum
1. The mass percentage of each element in aluminum oxide Al₂O₃ are:
i. The mass percent of Al in Al₂O₃ is 52.9%
ii. The mass percent of O in Al₂O₃ is 47.1%
2. The mass of Al in 3.62 g of Al₂O₃ is 1.73 g
1i. Determination of the percentage of Al
Molar mass of Al₂O₃ = (2×27) + (3×16) = 102 g/mol Mass of Al of Al₂O₃ = 2 × 27 = 54 gPercentage of Al =?Percentage = mass / mass of sample × 100
Percentage of Al = (54 / 102) × 100
Percentage of Al = 52.9%
1ii. Determination of the percentage of O
Molar mass of Al₂O₃ = 102 g/mol Mass of O of Al₂O₃ = 3 × 16 = 48 gPercentage of O =?Percentage = mass / mass of sample × 100
Percentage of O = (48 / 102) × 100
Percentage of O = 47.1%
2. Determination of the mass of Al in 3.62 g of Al₂O₃.
102 g of Al₂O₃ contains 54 g of Al.
Therefore,
3.62 g of Al₂O₃ will contain = (3.62 × 54) / 102 = 1.73 g of Al.
Thus, 1.73 g of Al is present in 3.62 g of Al₂O₃.
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1. List the ketose carbon(s) that is(are) reduced with NaBH4.
Answer:
ehh im nit sure but here!
Explanation:
C= ( F - 32) / 1.8
86 F = ?
Answer:
C = 30
Explanation:
C = (86 - 32)/1.8
C = (54)/1.8
C = 30
patient requires blood transfusion. what is the next thing to do? discuss
Explain in your own words:
i. Sublimation
ii. Condensation
iii. Melting