Answer:
There are 6.022x10^23 molecules
What is Displacement reaction . Explain with an example.
Explanation:
A displacement reaction is the one wherein the atom or a set of atoms is displaced by another atom in a molecule. For instance, when iron is added to a copper sulphate solution, it displaces the copper metal. A + B-C → A-C + B.
Ganciclovir is used to treat cytomegalovirus, a deadly viral infection common in immunocompromised patients. The doctor places an order for a dose of 2.5 mg/kg of body weight. What dose will the nurse administer for a 141 lb patient?
A. 160 mg
B. 56.4 mg
C. 352 mg
D. 124 mg
Answer:
A.160mgs
Explanation:
First you convert the lbs to kgs, 141lbs=63.957kgs
then you divide 63.957kgs by 2.5 which is 159.89
round up to 160, 160mgs is the correct dosage.
The dose that will the nurse administers for a 141 lb patient is 160mgs. The correct option is A.
What is a virus?
A virus is an entity that is only become alive when it gets a living host. It takes survives in its host and affects the body of the host. They are microorganisms that can not be seen by direct eyes. Viruses are harmful microorganisms. They are very deadly and they transmit through breath.
Medication, contain treatment that includes drugs and therapies to recover the patient from the disease. It is a proper process that includes timely procedures.
First, you convert the lbs to kgs, 141lbs = 63.957kgs
Then you divide 63.957 kgs by 2.5 which is 159.89 round up to 160, 160mgs is the correct dosage.
Thus, the correct option is A. 160 mg.
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What is the Ka expression for HCO3 ?
I want the solve of this problem
Answer:
the answer of this question is B
How mant grams are there in 7.15 x 10^24 molecules of water?
A)11.88g
B)214.02g
C)0.66g
D) 1.29 x 10^26g
E)3.97 x 10^23 g
Answer:
B. 214.02
Explanation:
1 mol of water weighs 18.015 gm and contains 6.023 × 10²³ molecules
From question, We have 7.15 × 10²⁴ molecules
Dividing we get (7.15 × 10 ²⁴) ÷ ( 6.023 × 10²³) = 11.871 molecules
Now, Weight of water = 11.871 × 18.015 = 213.85 which is nearer to option B
Answer:
[tex]\boxed {\boxed {\sf B. \ 214 \ g }}[/tex]
Explanation:
We are asked to find the mass of a given number of water (H₂O) molecules.
1. Convert Molecules to MolesFirst, we convert molecules to moles. We will use 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 water. Therefore, there are 6.022 ×10²³ molecules of water in 1 mole of water.
We will convert using dimensional analysis, so we must set up a ratio using the underlined information.
[tex]\frac {6.022 \times 10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}[/tex]
We are converting 7.15 × 10²⁴ molecules of water to moles, so we multiply the ratio by that value.
[tex]7.15 \times 10^{24} \ molecules \ H_2O*\frac {6.022 \times 10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}[/tex]
Flip the ratio so the units of molecules of water cancel each other out.
[tex]7.15 \times 10^{24} \ molecules \ H_2O*\frac {1 \ mol \ H_2O} {6.022 \times 10^{23} \ molecules \ H_2O}[/tex]
[tex]7.15 \times 10^{24} *\frac {1 \ mol \ H_2O} {6.022 \times 10^{23} }[/tex]
[tex]\frac {7.15 \times 10^{24}} {6.022 \times 10^{23} } \ mol \ H_2O[/tex]
[tex]11.87313185\ mol \ H_2O[/tex]
2. Convert Moles to GramsNext, we convert moles to grams. We will use the molar mass. This is the mass of 1 mole of a substance. These values are found on the Periodic Table. They are equivalent to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up the molar masses of the individual elements in water: hydrogen and oxygen.
H: 1.008 g/mol O: 15.999 g/molThere is a subscript of 2 after H, so there 2 moles of hydrogen in 1 mole of water. Multiply the molar mass by 2 before adding oxygen's molar mass.
H₂: 1.008 * 2 = 2.016 g/mol H₂O: 2.016 + 15.999 = 18.015 g/molWe convert using dimensional analysis again and set up another ratio.
[tex]\frac {18.015 \ g \ H_2O}{ 1 \ mol \ H_2O}[/tex]
Multiply by the number of moles we just calculated.
[tex]11.87313185 \ mol \ H_2O *\frac {18.015 \ g \ H_2O}{ 1 \ mol \ H_2O}[/tex]
The units of moles of water cancel.
[tex]11.87313185 *\frac {18.015 \ g \ H_2O}{ 1 }[/tex]
[tex]213.8944703 \ g \ H_2O[/tex]
The original measurement of molecules has 3 significant figures, so our answer must have the same. For the number we found, that is the one place. The 8 in the tenths place tells us to round the 3 up to a 4.
[tex]214 \ g \ H_2O[/tex]
There are approximately 214 grams of water and choice B is correct.
4. In KCl, how are the valence electrons distributed?
O A. The electrons are shared between many K and Cl ions, creating a "sea of electrons."
B. The electrons are transferred from K to CI.
O c. The electrons are equally shared between K and Cl, forming a covalent bond.
D. The electrons are unequally shared between K and Cl, forming a polar covalent bond.
Answer:
Since KCl is an ionic compound, there is transfer of electrons from K to Cl. Thus right answer should be (B)
KCl is a chemical called potassium chloride that has been known to be an ionic compound. The valence electrons ion KCl gets transferred from K to Cl ion. Thus, option B is correct.
What is an ionic bond?An ionic bond is said to be a type of chemical bond that involves the gain and loss of the electron in the valence shell of the atom species. It involves the bond formation between the ions.
The ions with opposite charges, carrying a positive and negative are said to bond by accepting and donating their electrons to achieve the noble-gas (electronic) configuration.
In KCl, potassium has more electrons and can donate it to chlorine species as the latter lacks electrons. Chlorine accepts electrons and in the process acquires a negative charge, whereas potassium gains a positive charge.
Therefore, option B. the KCl involves ionic bonds by transferring electrons.
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Propose routes to the following compounds from propyl bromide and any necessary organic or inorganic reagents:
a. propyllithium
b. propylmagnesium bromide
c. propylzinc bromide
d. Dipropylzinc
A container with a specific volume “V” changes to “2V”. What happens to the average distance between gas molecules? Assume that pressure and temperature of the gas remain constant.
Water
(liquid)
Pressure (atm)
1
05-
025-
Ice
( (solid)
Water vapor
(gas)
10
101
100
Temperature (°C)
What do the sections between the lines on a phase diagram represent?
A. The regions in which temperature and pressure change a
substance's phase
B. The conditions in which a substance exists in a certain phase
C. The ranges where temperature and pressure are constant in a
substance
D. The areas in which the kinetic energy of a substance is constant
Answer:A
Explanation:
I can distunguish between elements, compounds and mixtures.
3.1 I can describe what elements anre and give examples of them.
3.2 I can describe what mixtures are and give examples of them.
3.3 I can describe what compounds are and give examples of them.
0 0
This picture represents..
O a compound
O an element
O a mixture of elements
O a mixture of compounds
Answer:
an element
Explanation:
that is the answer yep
it represent an element
1.List three (3) importance of photosynthesis to our ecosystem. a) b) c)
Answer:
It is the number one source of oxygen in the atmosphere. It contributes to the carbon cycle between the earth, the oceans, plants and animals. It contributes to the symbiotic relationship between plants, humans and animals. It directly or indirectly affects most life on Earth
Answer:
three importance are
it helps in fixing and balancing the amount of carbon dioxide and oxygen in the atmosphere
it provides the nutrition to the plant
it helps the. plant in its growth
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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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...
What's the electron configuration of an N-3 ion?
A) [H]
B) [Ne]
C) [He]
D) [Ar]
Answer:
C) [He]
Explanation:
Answer:
B) Ne
Explanation:
took the test
Ammonia is produced by the reaction of nitrogen and hydrogen according to the equation
N2(g) + 3H2(g) → 2NH3(g)
Calculate the mass of ammonia produced when 27.0 g of nitrogen react with 12.0 g of hydrogen.
g NH3
Which is the excess reactant and how much of it will be left over when the reaction is complete?
Explanation:
Ammonia is produced by the reaction of nitrogen and hydrogen according to the equation
N2(g) + 3H2(g) → 2NH3(g)
Calculate the mass of ammonia produced when 27.0 g of nitrogen react with 12.0 g of hydrogen.
g NH3
Which is the excess reactant and how much of it will be left over when the reaction is complete?
Oceanography does not include the study of which of the following topics?
A.the relationship between the Sun, Moon, and Earth
B.the relationship between the atmosphere, Earth, and the oceans
C.the Earth's oceans
D.the plants and animals that live in the oceans
Answer:
A. The relationship between the Sun,Moon,and Earth
Explanation:
What is the systematic name of the following compound?
Li2S
Choose 1 answer:
А
Lithium sulfate
B В
Lithium sulfide
Dilithium sulfate
Dilithium sulfide
Explanation:
Lithium sulfide
if my answer helps you than mark me as brainliest.
If you wanted to increase the speed of
vaporization, you could
A. put the substance in the freezer.
B. place a lid on the substance.
C. heat the substance to the boiling point.
D. cool the substance to the freezing point.
>
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Answer:
C. heat the substance to the boiling point.
Answer:
heat the substance
Explanation:
What kinds of evidence might be used to conclude that you have isolated a new element?
The evidence that might be used to conclude that I have isolated a new element is the number of protons in the nucleus.
Chemical elements are different materials that have been found in nature that are characterized by having chemical characteristics different from other elements.
One way to know if I have found and isolated a new element is by showing that it does not have the same number of protons in the nucleus because this is what defines the characteristics of each element and each one has a different number of protons in the nucleus.
Therefore, the first thing I must do when I think I have found a new element is to isolate one of its atoms and check that it does not have the same number of protons in the nucleus as another element.
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A cation of 2 indicates that an element has Group of answer choices lost two neutrons. lost two protons. gained two electrons. lost two electrons. gained two protons.
Answer:
lost 2 electrons
Explanation:
A cation by definition is a positively charged ion. They are formed when a metal loses its electrons. A cation has more protons than electrons, giving it a net positive charge. So, it had to have lost 2 electrons to give it a positive charge of 2⁺.
A student wants to do a scientific research on how a nuclear fusion can be used as a power source on earth. What type of scientist does the student want to become?
A nuclear scientist because they are more focused on extracting the nuclear energy of atoms.
Which of the following is the correct net ionic equation for the formation of barium sulfate?
O B2+(aq) + SO42- (aq) → BaSO4 (s)
Ba2+(aq) + S2(aq) → Bas(s)
Be2+ (aq) + S042(aq) → BeSO4 (5)
Ba2+(aq) + SO42 (aq) → BaSO4 (5)
Answer:
Ba²+ (aq) + SO4²- (aq) --> BaSO4(s)
The net ionic equation for the formation of barium sulphate is Ba²⁺₍aq₎ + SO₄² ₍aq₎ → BaSO₄₍s₎. Therefore, option D is correct.
What is barium sulphate ?The inorganic substance having the chemical formula BaSO₄ is called barium sulfate. It is a tasteless, crystalline white substance that is insoluble in water. The main commercial source of barium and the materials made from it is the mineral barite, which is where it naturally occurs.
The use of barium sulfate aids in the diagnosis or discovery of issues with the esophagus, stomach, and bowels. It is a contrast material for radiography. To make the various bodily components clearly visible, contrast chemicals are used.
A barite-derived metallic compound with a silvery white color. In barium swallows and barium enemas, it is diluted with water to aid visualize the digestive tract on an x-ray.
Thus, option D is correct.
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7. Which of the following is not part of the proper protocol for using acids and bases?
A. Wearing protective clothing while handling
B. Storing acids and bases below 10°C
O C. Storing acids and bases in separate areas
D. Add acid to water, not water to acid
Answer:
D. Add acid to water, not water to acid
45. Show that the acceleration of a hamster is 5 m/s2 when it
increases its velocity from rest to 10 m/s in 2 s.
The acceleration of the hamster is 5 m/s².
Acceleration is the rate of change of velocity per unit of time.
Given:
Initial velocity (v₀): 0 m/s (rest)Final velocity (v): 10 m/sTime elapsed (t): 2 sWe can calculate the acceleration of the hamster using the following expression:
[tex]a = \frac{v-v_0}{t} =\frac{10m/s-0m/s}{2s} = 5 m/s^{2}[/tex]
The acceleration of the hamster is 5 m/s².
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What kinds of questions cannot be answered by chemistry
If the PH is 5.85.how do I calculate for an acid ?[H^+]
Answer:
if its under 7 then it's an acid you neek over 7 is alkaline
Things around you. All around you there is matter. The chair you are sitting on, air and
water are all matter. Almost everything that you see is matter. Anything that has mass
and takes up space is called matter.
What do we call something that has mass and takes up space?
Answer:
Hi Lovelys!!
Answers down below!!
Explanation:
There are two answer my me: Matter and Volume
Matter is anything that has mass and takes up space. Mass gives an object the property of weight and inertia (resistance to change in the motion of an object).
Volume simply refers to the space an object takes up. Depending on the physical state of an object, there are a couple ways to measure volume. If we are trying to measure the volume of a box, for instance, we would multiply the length of the box by its height and by its width.
Hope this helps!! =3
Have a wonderful day, evening, or night!! <3
An organized method scientists use to solve problems and test
hypotheses
hypothesis
scientific process
conclusion
experiment
Explanation:
Hypothesis is answer.
Have a great day
a 2.00 mL sample of a substance A has a density of 18.4g/mL and a 5.00 mL sample of substance B has a density of 35.5g/mL. do you have an equal mass of substances A and b?
this question made my brain hurt. please explain :(
Answer:
no
Explanation:
make use of this formula to find the mass of each sample.
m=density*volume
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