Answer:
» It contains two atoms of sodium sulphate
» It contains 10 molecules of water.
PLEASE ANSWER ASAP NEED ANSWER!!!!!!!!!!!!!! 75 POINTS
Which statement about pure substances and molecules is correct?
A. Pure substances cannot be molecules.
B. All molecules are pure substances.
C. Molecules cannot be pure substances.
D. All pure substances are molecules.
Answer:
D. All pure substances are molecules.
The correct statement about pure substances is; "All molecules are pure substances."
A pure substance contains exactly the same type of atoms. In a molecule, there can only be a particular combination of atoms.
For instance, a molecule of HCl can only contain chlorine and hydrogen atoms.
This means that every molecules are also pure substances.
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Question 25 of 30
Several dyes were mixed together and dissolved in water. You need to
determine which dyes are in the solution, but not separate the entire mixture.
How can you separate out a small sample of the dyes for identification
purposes, but not separate the entire mixture?
A. By distilling the dyes
B. By filtering the dyes
C. By using oils to distill the dyes
D. By using chromatography
SUBMIT
We can separate out a small sample of the dyes for identification purposes, but not separate the entire mixture by using chromatography.
What is Chromatography?Chromatography is a technique of separation of mixtures of liquids according to the nature of those liquids.
To get the process started, the mixture is dissolved in a substance called the mobile phase, which carries it through a second substance called the stationary phase.
The different components of the mixture travel through the stationary phase at different speeds, causing them to separate from one another. The nature of the specific mobile and stationary phases determines which substances travel more quickly or slowly, and is how they are separated. These different travel times are termed retention time.
Therefore, We can separate out a small sample of the dyes for identification purposes, but not separate the entire mixture by using chromatography.
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draw the atomic structure of 10 elements and show Electronic configuration.......
Answer:
ज
Explanation:
ूअूिkzkzkksksosawwhsusisisisisisiisisisisisisiisisisis
Dieldrin is a pesticide that is effective in killing?
Answer:
fddoiiijjjjjjjhhggggrrddffgghuuiii
b. Use the balanced equation to answer the following questions.
CuSO4(aq) + 2NaOH(aq) —->Cu(OH)2(s) + Na2SO4(aq)
i. What is the ratio of moles of CuSO4 to moles of NaOH?
ii. If 638.44 g CuSO4 reacts with 240.0 NaOH, which is the limiting reagent?
iii. Using the limiting reagent to determine how many grams of Cu(OH)2 should precipitate out in the reaction.
iv. If only 174.6g of Cu(OH)2 precipitate were actually collected from the reaction, what would the percent yield be?
Answer:
i. 1 : 2
ii. NaOH is the limiting reagent
iii. 292.5g
iv. 59.69%
Explanation:
I have the detailed and self-explanatory workings. will snap and post later. Battery percent at 15%, flashlight not working.
1. The ratio of CuSO₄ to NaOH is 1 : 2
2. The limiting reactant is NaOH.
3. The mass of Cu(OH)₂ that will precipitate out is 292.5 g.
4. The percentage yield of Cu(OH)₂ is 59.7%
1. Determination of the ratio of CuSO₄ to NaOH.
CuSO₄ + 2NaOH —> Cu(OH)₂ + Na₂SO₄
From the balanced equation above, we can see that the ratio of CuSO₄ to NaOH is 1 : 2
2. Determination of the limiting reactant.
CuSO₄ + 2NaOH —> Cu(OH)₂ + Na₂SO₄
Molar mass of CuSO₄ = 63.5 + 32 + (16×4) = 159.5 g/mol
Mass of CuSO₄ from the balanced equation = 1 × 159.5 = 159.5 g
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
Mass of NaOH from the balanced equation = 2 × 40 = 80 g
From the balanced equation above,
159.5 g of CuSO₄ reacted with 80 g of NaOH.
Therefore,
638.44 g of CuSO₄ will react with = (638.44 × 80) / 159.5 = 320.22 g of NaOH.
From the calculations made above, we can see that a higher mass (i.e 320.22 g) of NaOH than what was given (i.e 240 g) is needed to react completely with 638.44 g of CuSO₄.
Therefore, NaOH is the limiting reactant.
3. Determination of the mass of Cu(OH)₂ that will precipitate out.
CuSO₄ + 2NaOH —> Cu(OH)₂ + Na₂SO₄
Molar mass of Cu(OH)₂ = 63.5 + 2(16 + 1) = 97.5 g/mol
Mass of Cu(OH)₂ from the balanced equation = 1 × 97.5 = 97.5 g
From the balanced equation above,
80 g of NaOH reacted to produce 97.5 g of Cu(OH)₂.
Therefore,
240 g of NaOH will react to produce = (240 × 97.5) / 80 = 292.5 g of Cu(OH)₂
Thus, 292.5 g of Cu(OH)₂ precipitated out of the reaction.
4. Determination of the percentage yield.
Actual yield of Cu(OH)₂ = 174.6 gTheoretical yield of Cu(OH)₂ = 292.5 gPercentage yield of Cu(OH)₂ =?Percentage yield = (Actual /Theoretical) × 100
Percentage yield of Cu(OH)₂ = (174.6 / 292.5) × 100
Percentage yield of Cu(OH)₂ = 59.7%
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Neha and Reha are playing see-saw. Neha is sitting 60 cm away from the fulcrum and Reha is sitting 40 cm away from the fulcrum. Calculate the effort that Reha should apply to lift Neha. The weight of Neha is 360 N.
Answer:
Reha should apply 540 N to lift Neha.
Explanation:
L = 360 N
LD = 60 m
E =?
ED = 40m
NOW
L * LD = E * ED
360 *60 = E*40
21600/40 = E
540 N = E
A variable parameter
a. does not affect the result.
b. is the factor that changes in an experiment.
C. cannot change.
d. is rarely included in experiments.
Answer
b.
Explanation:
variable means change bro
I need help on this question plzzz
Answer:
76 ml
0.076 L
Explanation:
hope that helps
Answer:
76 for the first one at least I think
Which method is used to separate the following mixture (a) water + kerosene
Answer:
The separation of kerosene, oil, and water are immiscible liquids, so they can be separated funnel.
when two atoms share four valence electrons the shared electrons form a/an ____
How can the Swartz process be modified to work for bacteria? Explain.
Answer:
https://swartzbiotechnologylab.sites.stanford.edu/research
Explanation:
Alkyl chlorides and alkyl bromides are typically transformed into alkyl fluorides in the organic reaction known as the Swarts Reaction.
Swartz reaction?Frederick Jean Edmond Swarts first reported this procedure in 1892. Heating the alkyl chloride or alkyl bromide in the presence of heavy metal fluorides like AGF, Hg2F2, CoF2, or SbF3 causes this reaction.
Swartz process can be used to modify work for bacteria. Bacterial biofilms are collections of microorganisms where the cells are immersed in an extracellular polymeric matrix that the bacteria have self-produced.
In contrast to planktonic bacteria, which are in a state of free movement in a bulk solution, this situation is very different.
Applications:
In this process, alkyl fluorides are created.Fluorinated aliphatic organic molecules, or Freons, are produced via a different variation of the same process.Anhydrous hydrogen fluoride is fluorinated to produce Freons in the presence of antimony salts, which exhibit the oxidation states +3 and +5.Therefore, Alkyl chlorides and alkyl bromides are typically transformed into alkyl fluorides in the organic reaction known as the Swarts Reaction.
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the internacional system of units is based on ?
Answer:
The international system of units is basic on 7 units.
Hope it helps you.Which of the following atoms is expected to have two unpaired electrons?
Al
Mg
Na
None of the above
Answer:
none of the above answers
How many inches are in 4.5 miles?
Am element has 18 electrons ,20 neutrons and a charge of -2.what is the mass number?..a.38 b.40 c.32 d.39
Answer:
Surely you must have a Periodic Table beside you....?
a=38
Explanation:
You gots Z=18, the atomic number, where Z is the number of nuclear protons. The number of protons defines the element....and thus we got calcium....
....and with 20 neutrons we got the 38Ca isotope....the which is rather short-lived...
Hello please I need help
how we can separate sand and water with the help of evaporation.
Answer:
By filtering
Explanation:
Take one cup of mixture of sand and water , filter using a cotton cloth ,
how many hours are in 25 years?
Loss of atmospheric ozone has led to an ozone "hole" over Antarctica. The process occurs in part by three consecutive reactions. (Each of the reactants and products in these reactions are gases.)
(1) Chlorine atoms react with ozone (O3) to form chlorine monoxide and molecular oxygen.
(2) Chlorine monoxide forms ClOOCl.
(3) ClOOCl absorbs sunlight and breaks into chlorine atoms and molecular oxygen. If the coefficient for a particular substance is "1", do not write the "1" in the balanced equation. For example, instead of writing "1Cl(g)", simply write "Cl(g)".
(a) Write a balanced equation for each step, including the state of each molecule.
(b) Write an overall balanced equation for the sequence.
Ozone O₃ consists of a strong reactive gas made up of three atoms of oxygen. Ozone occurs on the Earth as natural and man-made gas.
Ozone impacts life on Earth in positive or harmful ways depending upon its location in the atmosphere.
From the information given, we are to balance the reactant and the product that leads to the formation of Ozone by following each step.
Step 1:
2Cl° + 2O₃ 2ClO° + 2O₂
Chlorine molecular
monooxide oxygen
Step 2:
2ClO° ClOOCl
Step 3:
ClOOCl + sunlight → 2Cl° + O₂
(b)
The Overall balanced equation can be expressed as:
2O₃ → 3O₂
Therefore, from the above explanation we can see the step by step process for the balanced equation and the overall balanced equation.
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Which property altered during a chemical change is not altered during a physical change?
A. composition of the matter
B. temperature of the matter
C. volume of the matter
D. phase of the matter
The property altered during a chemical change that is not altered during a physical change is composition of the matter.
A physical change is one in which no new substance is formed and it is easily reversible.
A chemical change is one that is not easily reversible and no new substance is formed. It may be accompanied by absorption or evolution of heat.
The composition of a substance changes during a chemical change because bonds between atoms break and new bonds are formed. This does not occur during a physical change.
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6. Heat from the sun reaches to us by
(a) radiation
(b) conduction
(c) convection
(d) all of these
PS. the one who gets it correct will be followed by me and also be marked as the brainliest!
Answer:
radiation
....
.
.
.
.hi how r u
Is my answer correct
Answer:
Radiation
Explanation:
Heat from the sun reaches is by the process of radiation
Illustrate the law of law of multiple proportions using the formation of SO2 and SO3 by sulphur and oxygen
As illustrated from law of multiple proportion, the mass of the oxygen which combined with a fixed mass of the sulphur is in simple whole number ratio of 2 is to 3 (2:3).
The law of Multiple proportion states that when two elements combine to form more than one compound, the mass of the second element, which combines with a fixed mass of the first element, will always be ratios of small whole numbers.
To illustrate the law of multiple proportion from sulphur and oxygen, we use the given compounds.
The reaction of oxygen with sulphur to form SO₂ and SO₃:
[tex]S \ + \ O_2 \ -----> SO_2\\\\2SO_2 \ + \ O_2 \ ---> \ 2SO_3[/tex]
atomic mass of oxygen = 16 g
atomic mass of sulphur = 32 g
In the formation of SO₂:mass of sulphur = 32 g and mass of oxygen = (2x16) = 32 g
In the formation of SO₃:mass of sulphur = 32 g and mass of oxygen = (3 x 16) = 48 g
Notice, while mass of sulphur is constant, mass of oxygen changed.
The ratio of mass of oxygen in the given two compounds = 32g : 48g = 2:3
Thus, based on the law of multiple proportion, the mass of the oxygen which combined with a fixed mass of the sulphur is in simple whole number ratio of 2 is to 3 (2:3).
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calculate mass of MnO2 if 1 mole of KMnO4 completely burnt. 2KMnO4 -> K2MnO4+MnO2+O2
Answer: 80 grams
Explanation:
2KMnO4 -> K2MnO4+MnO2+O2
2 moles of KMnO4 would produce 1 mole of MnO2, so 1 mole of KMnO4 would produce 0.5 moles of MnO4. The molar mass of MnO4 is 160 g/mole. 1/2 mole of KMnO4 would therefore be (160 g/mole)*(0.5 moles) = 80 grams.
for the equation given, how many grams of methane will react with a 125g of oxygen
CH4 (g) + 2O2(g) -> CO2(g) +2H2O
Answer:
16
Explanation:
1) in the given equation CH₄+2O₂⇒ 2H₂O+CO₂;
M(CH₄)=12+4=16 (g/mol); M(O₂)=32 (g/mol);
2) if m(O₂)=125 gr., then ν(O₂)=m(O₂)/M(O₂)=125/32≈3.90625 (moles);
3) if in the given equation 'ν' of O₂ is 2, then the 'ν' of CH₄ is 1;
4) m(CH₄)=ν(CH₄)*M(CH₄)=1*16=16 (gr.).
Which of the following is a feature of a Type IV flotation device?
Answer:
A Type IV PFD is an approved device designed to be thrown to a person in the water. It is not designed to be worn. It is designed to have at least 16.5 pounds of buoyancy. The most com- mon Type IV PFD is a buoyant cushion.
A semiconducting material is composed of 105 g of Ga, 80 g of Al, and 92.0 g of As. Which element has the largest number of atoms in this material?
Answer:
What is Acellus? Acellus is a learning accelerator. It uses video-based lessons with cutting-edge technology to accelerate learning, elevate standardized test scores, reduce dropout rates and transition more students into careers and college.
The following reaction is exothermic. 2 N2O(g) 2 N2(g) O2(g) This means the reaction: 56) A) will be spontaneous only at low temperatures B) is not spontaneous at any temperature C) will be spontaneous only at high temperature D) will be spontaneous at all temperatures E) cannot determine without temperature
For exothermic processes, spontaneity will only occur if the entropy positive with all temperature or if the entropy is negative with only low temperature.
Since the given equation decomposed from 2 moles of gas into 3 moles of gas, we know that entropy is positive. Thus the reaction will be spontaneous at all temperature.
D is the answer
What would most likely happen if the kangaroo rats
were killed off and removed from the food chain?
Answer:
Explanation:
The number of cactus plants would increase.
A graduated cylinder is filled with 20ml of water. A rock is dropped in to the graduated cyclinder and the volume of water rises to 30ml
inside the graduated cylinder. The mass of the rock is 23g. What is the density of the rock?
2.3g/ml
0.77g/ml
5g/ml
1.15g/ml
Answer:
[tex]\boxed {\boxed {\sf 2.3 \ g/mL}}[/tex]
Explanation:
We are asked to find the density of a rock. Density is the substance's mass per unit volume. The formula for calculating density is:
[tex]\rho= \frac{m}{v}[/tex]
The mass of the rock is 23 grams. The volume was found using water displacement. A known amount of water was measured, the rock was added to the graduated cylinder, and the water level was recorded again. The volume is the difference between the final and initial water level. The graduated cylinder originally had 20 milliliters and the water rose to 30 milliliters.
volume = final water level - initial water level volume = 30 mL - 20 mLvolume = 10 mLNow we know the mass and the volume.
m= 23 g v= 10 mLSubstitute the values into the formula.
[tex]\rho= \frac{ 23 \ g }{30 \ mL}[/tex]
Divide.
[tex]\rho= 2.3 \ g/mL[/tex]
The density of the rock is 2.3 grams per milliliter.
In a year an adult cow produces around 3.571 x 10^27 molecules of methane CH4 a greenhouse gas how many moles of methane does this cow produce in a year
Answer:
[tex]\boxed{\boxed {\sf 5930.0 \ mol \ CH_4}}[/tex]
Explanation:
We are asked to find how many moles of methane (CH₄) a cow produces in a year. We must convert molecules of methane to moles of methane. We will do this using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance.
In this case, the particles are molecules of methane. There are 6.022 × 10²³ molecules of methane in 1 mole.
We will convert molecules to moles using dimensional analysis. Set up a ratio using Avogadro's Number.
[tex]\frac {6.022 \times 10^{23} \ molecules \ CH_4}{ 1 \ mol \ CH_4}[/tex]
We are converting 3.571 × 10²⁷ molecules of methane to moles, so we multiply the ratio by this value.
[tex]3.571 \times 10^ {27} \ molecules \ CH_4 *\frac {6.022 \times 10^{23} \ molecules \ CH_4}{ 1 \ mol \ CH_4}[/tex]
Flip the ratio. It is still the same value, but the units of molecules of methane cancel.
[tex]3.571 \times 10^ {27} \ molecules \ CH_4 *\frac { 1 \ mol \ CH_4}{6.022 \times 10^{23} \ molecules \ CH_4}[/tex]
[tex]3.571 \times 10^ {27} *\frac { 1 \ mol \ CH_4}{6.022 \times 10^{23} }[/tex]
[tex]\frac {3.571 \times 10^ {27}}{6.022 \times 10^{23} } \ mol \ CH_4[/tex]
[tex]5929.923613 \ mol \ CH_4[/tex]
The original measurement of molecules of methane( 3.571 × 10²⁷ molecules) has 4 significant figures, so our answer must have the same. For the number we calculated, that is the ones place. The 9 in the tenth place tells us to round the 9 in the ones place up to a 0, then the 2 in the tens place up to a 3.
[tex]5930 \ mol \ CH_4[/tex]
We must add a placeholder zero in the tenth place to reach 4 sig figs.
[tex]5930.0 \ mol \ CH_4[/tex]
The adult cow produces approximately 5930.0 moles of methane in a year.
