Answer:
This is not a true solution because the colloidal dispersion is not completely homogeneous, and it does not have uniform properties throughout.
Explanation:
hope i helped
compared to those
5. Electrons farther away from the nucleus in an atom have
closer to the nucleus.
O A. lower energy
OB. higher energy
O C. the same energy
O D. higher or lower energy, depending on the element
Explanation:
higher or lower energy, depending on the element
Answer:
B
Explanation:
List of choices for questions 20-24: A. (1) CH3MgBr, (2) H3O , (3) CH3MgBr, (4) H3O B. (1) LDA, (2) CH3I, (3) H3O C. (1) CH3MgBr, (2) H3O , (3) NaBH4, (4) H3O D. (1) DIBAH, (2) H3O E. (1) NaOH, heat, (2) SOCl2, (3) CH
Answer:
h30
Explanation:
Which of these outcomes is conclusive evidence that mixing sugar in water is a physical change?
Answer:
» Water changes from colorless to a pale colored solution.
» The solubility of water reduces because a saturated solution is formed.
» The freezing point of water decreases. [colligative property]
» The boiling point of water elevates [colligative property]
» The vapour pressure of water lowers [colligative property]
Explanation:
[tex].[/tex]
3(b) The balloon did not burst when it is pressed onto 100 nails because
1. the nails are not sharp
2.the surface area of 100 nails produce high pressure on the balloon
3. the larger surface area of 100 nails produce low pressure on the balloon
3(c) To reduce pressure on the contact surface, we must apply force onto the .................... surface area.
1.largest
2.smallest
3. Any size of
What are the differences of a physical change and a chemical change?
Answer:
a physical change only changes the look of something whereas a chemical change occurs when one thing has a reaction and it forms a new substance.
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.
Which list only includes terms that describe oxygen gas, O2?
A. element, molecule, pure substance
B. atom, compound, molecule
C. atom, element, molecule
D. compound, molecule, pure substance
Answer:
d
Explanation:
it just makes alot of sense and you got this
Oxygen is a gas that belongs to the chalcogen family and is a reactive non-metal. It is an element, molecule, or pure substance. Thus, option A is correct.
What is a pure substance?A pure substance is defined as a substance that cannot be physically separated into its constituent particles. They are known to have a definite and constant chemical composition. It can be a molecule, element, or compound.
An element is atomic species that cannot be broken into simple sub-particles by chemical processes. On the other hand, if an atomic element bonds to the same or different atom it forms a molecule.
Oxygen gas is an element composed of two atoms of oxygen and is a molecule as the two atoms are linked chemically. It is also a pure substance as it contains the same element.
Therefore, option A. oxygen gas is a pure substance, an element, and a molecule.
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Describe the differences between models and scientific laws and theories. (
Answer:
Scientific laws and theories have different jobs to do. A scientific law predicts the results of certain initial conditions. ... In simplest terms, a law predicts what happens while a theory proposes why. A theory will never grow up into a law, though the development of one often triggers progress on
Explanation:
The specific gravity of a vegetable oil is 0.92. What is the massgrams, of 330 mL of vegetable oil?
Answer:
HOPE THIS ANSWER WILL HELP YOU
Phosphorous-32 has a half life of 14.3 days while radon-222 has a half-life of 3.8 days, so phosphorous-32 is considered more active.
a. True
b. False
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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9. Hydrogen is 99% H, 0.8% ?H, and 0.2% H. Calculate its average atomic mass.
Answer: Technically, this cannot be answered, since none of the H atoms have a mass number assigned. With the assumption noted delow, I calculate 1.012 as the average atomic mass.
Explanation:
My answer is based on assumed masses for the three H isotopes:
1H : 1 AMU
2H: 2 AMU Deuterium
3H: 3AMU Tritium
AMU Rel Abund. Wt. Avg
1H 1 99.00% 0.99
2H 2 0.80% 0.016
3H 3 0.20% 0.006
Sum 1.012
the internacional system of units is based on ?
Answer:
The international system of units is basic on 7 units.
Hope it helps you.Is thallium, TI, a solid, liquid, or gas?
Answer:
Thallium is a Solid
Hope it helps
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:DD
If I have a bottle of compound X at a pressure of 45 atm and temperature of 100 °C, what will happen if I raise the temperature to 400 °C?*
Answer:
55/350
Explanation:
because the answer is in the middle of 50and 400
11) Calcium Chloride, CaCl2, can be used instead of road salt to melt the ice on roads during the winter. To determine how much calcium chloride had been used on a nearby road, a student took a sample of slush to analyze. The sample had a mass of 23.47g. When the solution was evaporated, the residue had a mass of 4.58g (assume that no other solutes were present).
a) What was the mass/mass percent of calcium chloride in the slush
b) How many grams of calcium chloride were present in 100g solution?
Answer:
What is that? I do not understand
Which of the following words means "the degree to which a measurement is precise and reliable"?
a. variable
b. accuracy
c. parameter
d. constant
What kinds of questions cannot be answered by chemistry
what is joules? plz help
The mass of an atom of element x is equivalent to the total mass of 7 hydrogen atoms
What is the correct clases for this drugs
Promethazine
heelp me please
Answer:
MedlinePlus Drugs Information
Explanation:
Promethazine is in a class of medication called phenothiazines
Element X forms the ion X22- What is the formula of the covalent compound X forms with chlorine?
A XCI
B XCl2
C XCl3
D XCl4
Answer:
the answer is mostly option a)XCl
Explanation:
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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What is 47.35 dL= mL?
Answer:
4.735 litres
Explanation:
10 dL = 1 litre
47.35 dL = 47.35/10 = 4.735 litres
Which of the following statements is incorrect for the reaction of 1,3- butadiene with a substituted alkene CH2=CHX when X is a nitro group?
Answer:
hugsvsbsbbsnjsjsnsbsbbzbd
Assuming equimolar quantities of reactants, which compound will react to the greatest extent with boron trifluoride (BF3) in a Lewis acid-base reaction
To solve such this we must know the concept of acid-base reaction. Therefore, NH[tex]_3[/tex] is the compound that will react to the greatest extent with boron trifluoride (BF[tex]_3[/tex]) in a Lewis acid-base reaction.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
NH[tex]_3[/tex] is an example of a Lewis Base that will react extensively with BF[tex]_3[/tex] to form the compound NH[tex]_3[/tex] + BF[tex]_3[/tex] → [B (NH[tex]_3[/tex])F[tex]_3[/tex]].
Therefore, NH[tex]_3[/tex] is the compound that will react to the greatest extent with boron trifluoride (BF[tex]_3[/tex]) in a Lewis acid-base reaction.
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Water is placed into a sealed jar and has a mass of 22.0 grams. The jar is placed in the freezer and the water turns to ice. The jar of ice is measured. The mass should be:
a. Slightly less than 22.0 grams
b. Exactly 22.0 grams
c. Slightly more than 22.0 grams
exactly 22.0 grams
because freezing is a physical change not a chemicl change..so nothing is taken away or added
ANSWER;
exactly 22.0 grams
because freezing is a physical change not a chemicl change..so nothing is taken away or added
why hydrogen has dual nature?
Answer:
Since hydrogen has a single electron in its valence shell, it exhibits dual nature. of the periodic table, or it can obtain one electron to complete its valency of two, such as halogens from Group 17. Since it only has one electron in its outer shell, hydrogen has a dual existence.
Explanation:
This means that, like a normal halogen, a hydrogen atom can easily gain an electron to form a complete outer shell, or lose an electron to form an alkali metal. Since it already has two electrons in its outer shell, hydrogen can be diatomic, rendering it unreactive.
Which of the following is an example of a change from gravitational potential
energy to kinetic energy?
Answer:
The speed of a roller coaster increases as gravity pulls it downhill and is greatest at its lowest point. Viewed in terms of energy, the roller-coaster-Earth system's gravitational potential energy is converted to kinetic energy
Explanation:
a ball held in the air is the example of a change from gravitational potential energy to kinetic energy.
h = 3.0 a + 28.2
A pediatrician uses the model above to estimate the height h of a girl, in inches, in terms of the girl's age a, in years. Based on the model, what is the estimated height of a 2-year-old girl?
Answer:
h = 34.2 in
Explanation:
h = 3.0a + 28.2
h = height of a girl.
a = age of a girl.
h = 3.0a + 28.2
h = 3.0(2) + 28.2
h = 6 + 28.2
h = 34.2
The estimated height of a 2-year-old girl is 34.2 in.
Hope this helps, thank you :) !!
