Answer:
the double helix of dna is, like its name, implies, in the shape of a helix which is essentially a three-dimensional spiral. the double comes from the fact that the helix is made of two long strands of dna that are intertwined—sort of like a twisted ladder.
Explanation:
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PLEASE HELP WITH CHEM !! Calculate the [OH-] of each of the following solutions given the [H+]. AND Classify each of the solutions in the question above as either acid, base, or neutral. AND FIND THE PH
pH, pOH, [H+], and [OH-] are all interrelated. For simplicity, we assume that we're working with aqueous solutions at 25 °C.
The following mathematical relations are relevant here:
pH = -log[H⁺]pOH = -log[OH⁻][H⁺] = 10^-pH[OH⁻] = 10^-pOHpH + pOH = 14[H⁺] × [OH⁻] = 10^-14A pH of 7 is neutral; a pH less than 7 is acidic; and a pH greater than 7 is basic.
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We are given four solutions of varying [H⁺], and we want to find the pH and the [OH⁻]. The pH will tell us whether the solution is neutral, an acid, or a base.
Finding the [OH⁻]Using the relationship [H⁺] × [OH⁻] = 10^-14, we can calculate the [OH⁻] of each solution by dividing 10^-14 by the given [H⁺]:
[OH⁻] = 10^-14/(3.3 × 10^-5) = 3.0 × 10^-10
[OH⁻] = 10^-14/(4.0 × 10^-8) = 2.5 × 10^-7
[OH⁻] = 10^-14/(7.2 × 10^-11) = 1.4 × 10^-4
[OH⁻] = 10^-14/(8.2 × 10^-4) = 1.2 × 10^-11
Note: While not indicated here, the units for [H⁺] and [OH⁻] are moles/liter (M).
Finding the pHTo find the pH of each solution, we take the negative logarithm of the [H⁺] with base 10, i.e., pH = -log₁₀[H⁺]:
pH = -log(3.3 × 10^-5) = 4.48
pH = -log(4.0 × 10^-8) = 7.40
pH = -log(7.2 × 10^-11) = 10.14
pH = -log(8.2 × 10^-4) = 3.09
Note that, for significant figures involving logarithms, the number of decimal places should equal the number of significant figures in the argument of our logarithm (the argument is what we're taking the -log of). Since we're taking the -log of quantities given to two significant figures, our corresponding pH values are given to two decimal places.
Acid, Base, or Neutral?As mentioned above, a pH = 7 is neutral, a pH < 7 is acidic, and a pH > 7 is basic.
4.48 < 7, so the first solution is an acid.
7.40 > 7, so the second solution is a base.
10.14 > 7, so the third solution is a base.
3.09 < 7, so the fourth solution is an acid.
Eight ounces (1 fl. Oz = 29.57 ml) of orange juice contains 160% of the recommended daily allowance of vitamin c (rda = 75-90 mg for adults). How many milliliters of the orange juice will provide 100% of the recommended daily allowance?
Determine from the balanced chemical reaction if
the derived mole ratio is correct or incorrect.
2FeBr3 + 3Na2S → Fe2S3 + 6NaBr
2 moles FeBra
3 moles Na2S
Answer:
Correct
Explanation:
According to the balanced chemical reaction, 2 mol FeBr3 are consumed for every 3 mol Na2S consumed.
A balanced equation obey the law of conservation of mass. The coefficients are the numbers which are added to balance the chemical equation. Here the given mole ratio is correct.
What is a balanced equation?An equation in which the number of atoms of reactants and products on both sides of the equation are balanced is defined as the balanced chemical equation. The coefficients which are added in front of the formula of each component represents the number of the species.
A molar ratio denotes the ratio between the amounts in moles of any two compounds involved in a balanced chemical reaction. By comparing the coefficient of each component, the mole ratio can be determined.
Here for the given reaction, for every 3 moles of Na₂S consumption 2 moles of FeBr₃ is also consumed. So the molar ratio of Na₂S to FeBr₃ is 2/3. Molar ratios are used as the conversion factors between products and reactants in many chemistry problems.
To know more about mole ratio, visit;
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3 points
5. Which of the following is true regarding the atoms involved in a
chemical reaction? *
a) During a chemical reaction, atoms will always be combined into much larger
molecules.
b) Some of the atoms will always be changed into a different type of atom by a
chemical reaction.
c) Some of the atoms present before the reaction will always be lost during a
chemical reaction.
d) The same number of each type of atom will always be present before and after a
chemical reaction takes place.
1. When _____
are added or removed from an atom, _____
is formed
Answer:
1.) protons or electrons 2.) ion
Explanation:
Making comparisons explain how Bohr’s model and the modern model of the atom differ in terms of the path of an electron.
Answer:
bohrs model ios inversly to the pressure an modren model is inversly to the force
Explanation:
Radioactivity is the -------------- disintegration of an atomic nucleus that releases energy to become stable *
a. Extraordinary
b. Normal
c. Ordinary
d. Spontaneous
Answer:
The answer is spontaneous.
What volume of 7.68 M NaOH (aq) will neutralize 1.15 L of 2.35 M H2SO4 (aq) ?
A)1.38 L
B)0.704 L
C)0.276 L
D)1.90 L
E)1.75 L
helpppppppppppp plzzzzzzzzzzz
Answer: we'll for sunny days that we'll be high pressure and for low pressure that we'll be cloudy and foggy moist days .
Explanation:
When no more solute can dissolve a solution is described as...
Answer:
Saturated solution
Explanation:
When is no more solute can be added then it is saturated solution
Which is an example of a chemical change?
A. heating a block of ice to form liquid water
B. heating a tungsten wire until it glows brightly
C. adding sugar crystals to water to form a clear, colorless liquid
D. passing an electric current through water to form hydrogen and oxygen
Answer:
D. passing an electric current through water to form hydrogen and oxygen
Explanation:
only one that's not just a physical change.
Where did scientists find most of the nitrogen that the rats ate?
Answer:
They found the rats near or in a lake or river, due to high concentration of nitrogen in their body.
METHANOL + ETHANOIC ACID
Help plzzZZZZ I really need help with this
Use the drop-down menus to complete the sentences.
The gain of electrons is called _________
The loss of electrons is called _________
Answer:
1.Reduction
2.oxidation
Explanation:
Answer:
Reduction
Oxidation
Explanation:
Which of the following is an example of a micro-habitat?
a
Abuela's vegetable garden on her huge farm
b
Ms. Steinmann's 200 gallon fish tank
c
woods behind the school
d
the algae growing on a seashell where tiny sea animals called plankton live
how many moles of solute are present in a 2 L of a 25M potassium nitrate solution
a. 0.5 moles
b. 2 moles
c. 50 moles
d. 25 moles
I NEED THIS ANSWER ASAP, im taking the quiz right now and i need HELPPP
Answer:
50 moles
Explanation:
took the quiz
What element is found in water?
1. Carbohydrate
2. Carbon
3. oxygen
Explanation:
3. the element is oxygen
A solution's hydrogen ion concentration is 1 x 10-SM.
What is the pH?
Answer:
the Ph is
Explanation:
90rn hub
A greenhouse is filled with air that cotains more carbon dixoide than normal air has. How might phothsyphness and plant growth be affeacted
Answer:
See explanation
Explanation:
We know that photosynthesis involves the combination of carbon dioxide and water in the presence of sunlight to yield glucose.
If the atmosphere is rich in carbon dioxide such as in a green house where air is filled with carbon dioxide, the rate of photosynthesis is increased.
As the rate of photosynthesis is increased, the growth of plants is also increased.
Hence, in a greenhouse where the air contains more carbon dioxide, the rate of plant growth increases.
1)Why do clouds usually form high in the air instead of near Earth's surface?
a) High in the atmosphere is less dense
b) High in the atmosphere contains less oxygen
c) High in the atmosphere is usually cooler
d) High in the atmosphere has less air pressure
Is aloe vera a living or non-living thing?
Answer:
It is a living plant
Explanation:
give an example of how an organism can use surface tension?
Answer:Insects, such as water striders, and spiders, such as fisher spiders, can glide or scamper across the surface of water. These critters are small enough that their weight can be supported almost entirely by surface tension, the relatively weak forces that hold water molecules together.
Explanation:
Answer:
Examples of surface tension Water striders are able to walk on top of water due to a combination of several factors. Water striders use the high surface tension of water and long, hydrophobic legs to help them stay above water. Water striders use this surface tension to their advantage through their highly adapted legs and distributed weight.
Explanation:
pls mark brainliest
Diamond is extremely hard and does not conduct electricity.
Which statement explains these properties?.
Answer:
C. It has no delocalised electrons and each carbon atom forms four covalent bonds with other carbon atoms.
Explanation:
Diamond is composed solely by carbon atoms. As the difference of electronegativity between atoms is 0, diamond is a fully covalent compound.The lack of electrical conductivity stems from a lack of available electrons, this means that there are no delocalised electrons.The information in the first point discards options A and D, while the second point discards option B. Thus the answer is option C.
a weather balloon expands from 3.00 L to 3.25 L. The atmospheric pressure is 0.96 atm. How much work was done on the surroundings?
I really, really, really need help with this. I've been struggling so much to understand thermochemistry!
Answer:
0.96
Explanation:
How do neutral metal atoms form ions?
Answer:
Neutral atoms can be turned into positively charged ions by removing one or more electrons. ... Atoms that gain extra electrons become negatively charged. A neutral chlorine atom, for example, contains 17 protons and 17 electrons. By adding one more electron we get a negatively charged Cl- ion with a net charge of -1.
Which diagram represents matter with a definite volume but no
definite shape?
i think it is Substance C
A
square is a diagram used to predict all possible allele combinations from a genetic
. Using this diagram, the phenotypes of offspring can be determined from the genotypes.
Answer:
AYAYYA
Explanation:
YEA
Ammonia (NH3) is widely used as a fertilizer and in many household cleaners. How much ammonia is produced when 5.81 mol of hydrogen gas react with an excess of nitrogen gas?
Answer:
65.841 g
Explanation:
The balanced equation for this reaction is;
N2 + 3H2 → 2NH3
From the question, we are interested in ammonia and the hydrogen gas.
From the equation
3 mol of H2 produces 2 mol of NH3
5.81 mol would produce x
Solving of x;
x = 5.81 * 2 / 3
x = 3.873 mol
Converting to mass;
Mass = Number of moles * molar mass
Mass = 3.873 * 17 = 65.841 g
The thermal energy of matter increases when ___.
A. Heat flows of the matter
B. The mass of the matter decreases
C. Heat flows into the matter
D. The temperature decreases