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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WILL BRAINLIST! NEED ANSWER!
• Why is it important to recycle metals?
A. to maintain sustainability
B. to create more tailings
C. to make sure ore remains renewable
D. to make it easier to extract ore from the ground
What is the balanced net ionic equation when aqueous solutions of Pb(NO3)2 and KBr are mixed and form a product
Answer:
KBr+Pb(NO3)2=? is an equation you can use.
Explanation:
can y’all please help me answer?
Answer:
It really depends on the situation. If you have 1000 elk and 2 wolves, they really would play a better role in killing off elk so that the elk population doesn't get over populated and diseased, causing a major population collapse. But if there were only 10 elk and 50 wolves, the wolves would play a very negative role on the population.
Hope this helps!
Explanation:
is H2O polar or non polar?
Answer:
Explanation:
H2O is a polar molecule
Answer:
polar covalent molecule
Explanation:
the unequal sharing of electrons between the atoms and the unsymmetrical shape of the molecule means that water has two pole a positive and a negative.
when would a scientist choose to conduct a controlled experiment
Answer:a scientist would choose to conduct a controlled experiment when it has all the necessary precautions and has the equipment to do so
Explanation:thank you
Plz mark for brainlist
When thinking about genetic engineering in agriculture, which type of issue has the most direct consequences? economical issues political issues social issues environmental issues
Explanation:
It is claimed that the increases in crop productivity brought about by genetic engineering can help relieve problems faced by farmers by decreasing the losses caused by pests, disease, weeds, and other stressors (Guerinot 2000).
Symbol of elements.
Explanation:
Gold Au
Copper Cu
Iron Fe
Magnesium Mg
Hydrogen H
Helium He
Mercury Hg
Iodine I
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
Based on the electron configuration of the two
atoms, predict the ratio of metal cationic (+) atom
to nonmetal anionic (-) atom in the compound.
Hydrogen 1s
Fluorine 1s22s22p5
A. 2:3
B. 1:2
C. 1:1
D. 3:2
Answer:
1 per 2 berarti a.2:3 berarti bagi bagi 1 22. 22 sama dengan 5
What volume of 0.100 M AgNO3 is
needed to react completely with
45.0 mL of 0.230 M Na2S?
2AgNO3 + Na2S → Ag2S + 2NaNO3
[?] mL AgNO3
Answer:
448mL AgNO3
Explanation:
M x V
n = 0.230 x .045 = 0.01
2AgNO3 + Na2S --> Ag2S+2NaNO3
1 mol Ag2S --> 2 moles AgNO3
.01 mol Ag2S --> ? moles AgNO3
.01x2/1=.02 moles AgNO3
Moles to L conversion is multiplying by 22.4L so we do .02 x 22.4=0.448L
Then we convert to mL so we multiply by 1000 (1000 x 0.448)
448mL AgNO3
There you go friend, good luck with chemistry :)
4 Mg & 3 Cu(NO3)2 + Cu(NO3)2 (aq) + Mg(NO3)2 (aq) + Cu (s)
balance?
Here you go
Mg + 2CuNO3 → Mg(NO3)2 + 2Cu
d. The animals such as snakes and tortoises are called reptilians. Why?
Answer:
Explanation : Reptiles are cold blooded animals, have scales on their body (instead of hair or fur) and are usually egg laying. (certain viper types and boas give birth to live young). So that is what makes animals reptiles.
Reptiles are cold-blooded creatures that often lay eggs and have scales on their bodies rather than hair or fur. (Some types of vipers and boas give birth to live young).
Due to these reasons animals are reptiles.
What are reptiles?
Air-breathing vertebrates known as reptiles have unique skin consisting of scales, bony plates, or a combination of the two.They comprise of tortoises, turtles, lizards, snakes, and crocodiles.All of them periodically shed their skin's outer covering. The temperature of their environment affects how they function.Reptiles do not maintain a steady internal body temperature, in contrast to birds and mammals. They cannot stay warm on a chilly day without fur or feathers, and they cannot cool themselves on a hot day without sweat glands or the ability to pant. Instead, they shift as needed between the sun and the shade. They stop moving around when the weather becomes colder. Reptiles are cold-blooded due to their slow metabolic rate and heat-seeking habit.
Thus, it can be concluded that animals such as snakes and tortoises are called reptilians.
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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:
Name of equipments that uses in crude oil distillation?
Explanation:
Crude oil distillation is a complex and capital-intensive process in petroleum refining. The crude oil distillation unit comprises distillation columns, pump-around loops, side strip.pers and a heat recovery system, known as the preheat train.
A force of 450 N accelerates a box across a frictionless surface at a rate of 15 m/s2. What is the mass of the box?
30 kg
6,750 kg
6,750 N
30 N
Answer:
30kg
Explanation:
F=ma
Force=mass×acceleration
40=m×15
m=450/15
m=30kg
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:
need answer asap ..
-20 points! asap please ..
Answer:
[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]
Explanation:
[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]
What's similar about the valence electrons of Carbon and Silicon?
Answer:
Explanation: Carbon and silicon BOTH come from Group 14 of the Periodic Table , i.e. both formally have the same number of valence electrons, 4 such electrons.........
ghjguygyughyyhghygyuguyg
what is involved fashion of male and female gametes to form a zygote which develops into an embryo
describe the atomic models above in terms of
a. location of nucleus
b.location of electrons
The specific heat of water is 4.184 J/gºC. How much energy (in
joules) is required to raise the temperature of 18g of H2O from
283K to 293K?
need help with this question asap :)
-20 points!..
A student reads that sodium atoms (Na) react with chlorine (Cl2) molecules to form the compound sodium chloride (NaCl). Which model should the student make to satisfy the Law of Conservation of Matter for the formation of sodium chloride, in simplest form?
Answer:
c
Explanation:
Law of Conservation of Matter for the formation of sodium chloride, in simplest form would be obeyed when 2 moles of sodium react with 1 ,mole of chlorine to form 2 moles of sodium chloride.
What is law of conservation of matter?According to law of conservation of matter, it is evident that matter is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of matter and energy are related as matter has mass and mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of matter is widely used in field of chemistry, fluid dynamics.
Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.
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help pls very simple
What are the gas laws? (Include Boyle's law, charles's law, gay lussac's law, an avogadro's law) Could someone please summarize these for me ples? Brainliest answer also yes
Answer:
Boyle's Law: When the pressure of a gas increases, the volume of the gas will decrease as long as the temperature and amount of gas are constant.
So basically pressure is inversely proportional to Volume, when one increases, the other decreases, vice versa.
Equation: [tex]P_{1} V_{1} = P_{2} V_{2}[/tex]
Charles Law: When the temperature of a gas increases, the volume of a gas will also increase if the pressure and amount of gas are constant.
So basically Temperature and volume are directly proportional.
Equation: [tex]\frac{V_{1}}{T_{1}} = \frac{V_{2} }{T_{2} }[/tex]
Gay Lussac's Law: When the temperature of a gas increases, the pressure of a gas also increases when volume and the amount of gas remain constant.
Basically, Temperature and Pressure are directly proportional.
Equation: [tex]\frac{P_{1}}{T_{1}} = \frac{P_{2} }{T_{2} }[/tex]
Avogadro's Law: The most intuitive gas law. When you increase the amount of gas, the volume will also increase.
Meaning the moles (amount of gas) is directly proportional to volume.
Equation: [tex]\frac{V_{1} }{n_{1} } = \frac{V_{2} }{n_{2} }[/tex] (n stands for moles)
There is a combined gas law and ideal gas law but those are just the gas laws mentioned above but combined together. These should be everything.
Answer:
Boyle Law is when pressure and volume have a reverse relationship when temperature is the same.Charles law is basically when volume and temperature have a relationship when the pressure is the same.Lussac Law is I think just when I pressure and temperature is directly tied together when the volume stays the same.I dont think there is any "avogadro law", there is only pressure volume and temperature.
Please give brainliest thanks :D
A sample of CO2 gas at 100 degrees Celsius has a volume of 250 mL at 760 mm Hg. How many moles of CO2 are present
There are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
HOW TO CALCULATE NUMBER OF MOLES:
The number of moles of a sample of gas can be calculated using the following formula:
PV = nRT
Where;
P = pressure of gas (atm)V = volume (L)n = number of moles (mol)R = gas law constant (0.0821 Latm/molK)T = temperature (K)According to this question;
P = 760mmHg = 1 atmT = 100°C = 100 + 273 = 373KV = 250mL = 0.250Ln = ?1 × 0.250 = n × 0.0821 × 373
0.250 = 30.62n
n = 0.250 ÷ 30.62
n = 8.16 × 10-³mol
Therefore, there are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
Learn more about number of moles at: https://brainly.com/question/4147359
NEED ANSWER! WILL BRAINLIST!
• Why are tailings an environmental concern?
A. They are a form of sewage that is found in agricultural runoff.
B. They are the remains from mining and contain harmful chemicals.
C. They are the waste products left over from fracking for natural gas.
D. They are a type of greenhouse gas that can enter the atmosphere.
B. They are the remains from mining and contain harmful chemicals.
Which compound contains ionic bonds?
No
No2
CaO
CO2
What holds the nucleus together? Group of answer choices alpha particles strong forces electrical forces between the protons beta particles
Answer:electrical forces between the protons
Explanation: The strong nuclear force pulls together protons and neutrons in the nucleus. At very small distances only, such as those inside the nucleus, this strong force overcomes the electromagnetic force, and prevents the electrical repulsion of protons from blowing the nucleus apart.
