Answer:
c
Explanation:
To achieve the highest return during recrystallization of a given solid, one must: Group of answer choices Add the minimum amount of boiling solvent necessary to dissolve the solid to be crystallized. Add an excess amount of cold solvent necessary to dissolve the solid to be crystallized. Add the minimum amount of cold solvent necessary to dissolve the solid to be crystallized. Add an excess amount of boiling solvent necessary to dissolve the solid to be crystallized.
Answer:
Option A
Explanation:
Addition of too much of solvent will make the solution dilute due to which the crystals will not form. Hence option D is incorrect
On the other hand adding a minimum amount of boiling solvent will give a saturated solution for recrystallization. Hence, option A is incorrect
Addition of cold solvent will lower the rate of formation of crystals. Hence, both option B and C are incorrect
Which of these space objects is the largest asteroid in the solar system?
Select one:
a. Pluto
b. Vesta
c. Ceres
d. Earth's Moon
Answer:
CERES is the latgest in the solar system
Explanation:
What is the mass of an iron piece that cools from 57.8 °C to 26.4°C while releasing
7160.2 J of heat? The specific heat capacity of iron is 0.444 J/gºC.
5.0 g of copper was heated from 20°C to 80°C. How much energy was used to heat Cu?
Answer:
100 J of energy are needed to heat the copper from 20∘C to 80∘C .
Below is a list of the first 10 residues of the B helix in myoglobin from different organisms.
Position 1 2 3 4 5 6 7 8 9 10
Human D I P G H G Q E V L
Chicken D I A G H G H E V L
Alligator K L P E H G H E V I
Turtle D L S A H G Q E V I
Tuna D Y T T M G G L V L
Carp D F E G T G G E V L
Based on this information, which positions (a) appear unable to tolerate substitutions, (b) can tolerate conservative substitution, and (c) are highly variable?
Answer:
i dont knoiwxplanation:
How will an increase in wind speed affect soil erosion?
O A Soil erosion will increase.
O B. Soil erosion will decrease.
O C. Soil erosion will completely stop.
OD Soil erosion will remain the same.
Answer:
A. Soil erosion will increase.
Option A is correct. Increase in wind speed will increase the rate of erosion.
The process of eroding, transferring, and depositing tiny particles as well as nutrients from the top layer of soil is known as soil erosion by wind.
In arid and semiarid regions, wind-driven soil erosion is a serious issue that impedes the environmental sustainability of animal husbandry and agriculture and threatens ecological security.
A wind that is blowing at 30 mph will erode at a rate that is more than 3 times faster than a wind that is blowing at 20 mph. As soil moisture rises, wind erosion declines. For instance, dry soil erodes approximately 1.3 times more quickly than soil with just enough moisture to support plant life.
Learn more about soil erosion;
https://brainly.com/question/9837143
A group of elements with similar properties, which usually falls into columns on the periodic table. A.period b.ductile c.atomis d.family
What type of muscle controls leg movement?
A. cardiac
B. striated
C. smooth
Answer:
c
Explanation:
for best accadimes
20.00 mL of a 0.077 M solution of silver nitrate, AgNO3, is mixed with 30.00 mL of a 0.043 M solution of sodium acetate, NaC2H3O2. Does a precipitate form? The Ksp of AgC2H3O2 is 2.5*10^-3.
Answer:
No, no precipitate is formed.
Explanation:
Hello there!
In this case, since the reaction between silver nitrate and sodium acetate is:
[tex]AgNO_3(aq)+NaC_2H_3O_2(aq)\rightarrow AgC_2H_3O_2(s)+NaNO_3(aq)[/tex]
In such a way, we can calculate the concentration of silver and acetate ions in the solution as shown below, and considering that the final total volume is 50.00 mL or 0.0500 L:
[tex][Ag^+]=\frac{20.00mL*0.077M}{50.00mL}=0.0308M[/tex]
[tex][C_2H_3O_2^-]=\frac{30.00mL*0.043M}{50.00mL}=0.0258M[/tex]
In such a way, we can calculate the precipitation quotient by:
[tex]Q=[Ag^+][C_2H_3O_2^-]=0.0308*0.0258=7.95x10^{-4}[/tex]
Which is smaller than Ksp and meaning that the precipitation does not occur.
Regards!
A compound has the following percentages by mass: barium, 58.8%; sulfur, 13.74%; oxygen, 27.43%. Determine the empirical formula.
Answer:
BaSO₄
Explanation:
Let's assume we have 100 g of the compound. If that's the case we would have:
58.8 g of Ba13.74 g of S27.43 g of ONow we convert the masses of each element into moles, using their respective molar masses:
58.8 g Ba ÷ 137.327 g/mol = 0.428 mol Ba13.74 g S ÷ 32 g/mol = 0.429 mol S27.43 g O ÷ 16 g/mol = 1.71 mol OWe divide those moles by the lowest number among them:
0.428 mol Ba / 0.428 = 10.429 mol S / 0.428 ≈ 11.71 mol O / 0.428 = 4We can express those results as Ba₁S₁O₄, meaning the empirical formula is thus BaSO₄.
1: Write the positive and negative ions that result when the following compounds are dissolved in an aqueous solution:
Compound:
1. Na2CO3(a)
2. FeBr3(aq)
3. Al2(SO4)3(aq)
2: Write word and formula equations for the reaction of sodium hydroxide, NaOH(aq) and phosphoric acid, H3PO4(aq). Word equation_________. Formula equation________. Why does this reaction occur?
Answer:
See explanation.
Explanation:
Hello there!
In this case, for the required chemical reactions, we proceed as follows, by considering that the left-handed elements stand for the cations and the right-handed ones for the anions:
1:
1. [tex]Na_2CO_3(aq)\rightarrow 2Na^+(aq)+(CO_3)^{2-}(aq)[/tex]
2. [tex]FeBr_3(aq)\rightarrow Fe^{3+}(aq)+3Br^-(aq)[/tex]
3. [tex]Al_2(SO_4)_3(aq)\rightarrow 2Al^{3+}(aq)+3(SO_4)^{2-}(aq)[/tex]
2: In this case, we can represent the formula equation first according to the neutralization reaction:
[tex]3NaOH(aq)+H_3PO_4(aq)\rightarrow Na_3PO_4(aq)+3H_2O(l)[/tex]
Which is worded as: three molecules of aqueous sodium hydroxide reacts with one molecule of aqueous phosphoric acid to yield one molecule of aqueous sodium chloride and three molecules of liquid water.
Regards!
What is the molarity of a solution that contains 0.220 moles KOH in 0.350 L of solution?
Answer:
0.628 M.
Explanation:
In order to solve this problem we need to keep in mind the definition of molarity:
Molarity = moles / litersWe are given both the number of moles and the volume of solution, meaning we can now proceed to calculate the molarity:
Molarity = 0.220 mol / 0.350 LMolarity = 0.628 MHelp please will mark brainliest!!
Answer:
90% of people marry there 7th grade love. since u have read this, u will be told good news tonight. if u don't pass this on nine comments your worst week starts now this isn't fake. apparently if u copy and paste this on ten comments in the next ten minutes you will have the best day of your life tomorrow. you will either get kissed or asked out in the next 53 minutes someone will say i love you.
Lisa made observations of stars at different times of the year. She noticed a lot of patterns that the fall, while she couldn't find any patterns in the summer. Why might this be?
Answer: Because not all stars are in patterns
Answer:
Because the stars do not come out when the temperature rises on Earth
Explanation:
Which organisms in soil helps relieve element so they can be recycled
Answer:
Bacteria are also involved in many processes that are indispensable for our life on Earth. Many of these processes have to do with the recycling (reuse) of chemical elements that have been here since the formation of the planet
Explanation:
I hope it will help you
Which of the following is an advantage of asexual reproduction compared to sexual reproduction?
Both will produce genetically identical offspring from the parent.
Sexual reproduction will increase genetic variability within a species.
Asexual reproduction requires less energy and will produce more offspring over time.
Sexual reproduction has minimal changes of mutations compared to asexual reproduction.
Explanation:
sexual reproduction has minimal changes of mutations compared to asexual reproduction
Answer:
sexual reproduction has minimal changes of mutations compared to asexual reproduction
I hope this helps
What mass of iron(III) oxide will be formed if 9.30 L of oxygen at STP react with excess iron?
Answer:
12
Explanation:
because that plot and the iron
Mechanical digestion begins in the_____ and involves physical processes, such as chewing.
Answer:
begins in the mouth
Identify some of the ways nuclear reaction equations differ from chemical reaction equations by matching each statement with the type of reaction it describes. You are currently in a sorting module. Turn off browse mode or quick nav, Tab to items, Space or Enter to pick up, Tab to move, Space or Enter to drop. Nuclear reaction equations Chemical reaction equations Answer Bank
Explanation:
Nuclear reactions are independent of the chemical form of the element. ... Some of the mass is converted into energy,according to the equation E = mc2 and the order of energy evolved during a nuclear reaction is much higher than that of a chemical reaction.
The energy given off in a chemical reaction is not in any way comparable to that of a nuclear reaction.
What is a nuclear reaction?A nuclear reaction is one in which the nucleus of an atom is transformed into the nucleus of one or more daughter nuclei. This differs from a a chemical reaction in which atoms are changed from one form to another.
Also, tremendous energy is given off when nuclear reactions occur. The energy given off in a chemical reaction is not in any way comparable to that of a nuclear reaction.
Learn more about nuclear reaction: https://brainly.com/question/9904853
Help me please jus tell me 1 2 3 etc for the answers thank you!
Answer:
1. lakes and rivers 2. groundwater 3. watershed 4. pollution
Explanation:
HC2HO3(aq)+H2O(l)⇄H3O+(aq)+C2HO3−(aq)
pKa=3.18
at 25°C
The equilibrium for the acid ionization of HC2HO3 is represented by the equation above. If 10.0mL of 0.20MHC2HO3 reacts with 5.0mL of 0.10MNaOH, which of the following could be used to calculate the correct pH of the resulting solution?
A) pH=pKa+log(0.100.20)
B) pH=pKa+log(0.0050×0.100.0100×0.20)
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
D) pH=pKa+log[((0.0050×0.10)+(0.0100×0.20)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Answer:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Explanation:
To find the pH of a buffer (The mixture of the weak acid and its conjugate base) we have to use Henderson-Hasselbalch equation:
pH = pKa + log [Base] / [Acid]
Where pKa is the pka of the buffer and [] is molar concentration of the species of the buffer
The [Base] is equal to the concentration of NaOH added:
0.10M * (0.005L / 0.015L)
And the concentration of the acid [Acid] is the initial concentration of the acid - the concentration of the NaOH added:
0.0100L * (0.20M)/0.0150L - 0.10M * (0.005L / 0.015L)
That means the pH of the buffer is:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Answer:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Explanation:
The equilibrium for the acid ionization of HC2HO3 is represented by the equation above. If 10.0mL of 0.20MHC2HO3 reacts with 5.0mL of 0.10MNaOH, which of the following could be used to calculate the correct pH of the resulting solution. pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
The _________ law of Newton’s Laws of Motion helps us add intensity to any activity.
A.
third
B.
first
C.
second
D.
second and third
Answer: A
The third law is the law of Newton’s Law of motion.
. A bar of copper has a mass of 216g and a volume of 24cm3. What is the density of copper?
in general, what do you think a subscript in a chemical formula tells you
Answer:
In the most simplest of words: The number of atoms in a molecule
ex) c6h12o6
There are 6 carbon atoms and oxygen atoms, 12 hydrogen atoms
Another example NH4
there are 1 nitrogen atoms and 4 hydrogen atom
Hope that answers your question
Explanation:
What is the name for Al(O)2?
Answer:
Aluminium oxide ________
Consider the balanced equation Zn + 2HCl ZnCl2 + H2 How many
moles of ZnCl2 will be produced if 2 moles of HCl are used?
Answer:
1 mole of ZnCl₂
Explanation:
Just from the stoichiometric equation/ balanced equation:
Zn(s) + 2HCl(aq) → ZnCl₂(s) + H₂(g)
1 mole 2 moles 1 mole 1 mole
Therefore: 2 moles of 2HCl produce 1 mole of ZnCl₂
When you add baking soda to vinegar, the mixture fizzes as carbon dioxide gas is produced. Suppose you added water to vinegar before you mixed it with the baking soda. Why will the rate of carbon dioxide production decrease?
Answer:
because the water would diloute the chemicals in the vinegar
Explanation:
Diagonal relationship is present between the lighter elements of periods
1) Second, third 2) Second, fourth 3) Third, fourth
4) third, fifth
Answer: The diagonal relationship is present between the lighter elements of periods second, thirds.
Explanation:
Elements which are present diagonally adjacent to each other in the second and third periods of the periodic table tends to show diagonal relationship as they have similar properties.
For example, Lithium is a second period element and magnesium is a third period element.
Hence, lithium and magnesium show diagonal relationship with each other.
Thus, we can conclude that diagonal relationship is present between the lighter elements of periods second, thirds.
The absorption of infrared (IR) radiation results in vibrations in the molecules or ions that make up a chemical sample. Vibrations cause bond lengths or angles to expand and contract. The energy of infrared radiation (i.e., frequency) required for a vibration depends on the type of bond and the mass of the atoms involved. Typically, the higher the bond order, the stronger the bond, and therefore, the more energy (i.e., higher frequency) required to make the bond vibrate. Also, lighter atoms vibrate at higher frequencies than heavier atoms. The order of vibrational frequencies (from largest to smallest) of the given carbon-nitrogen and carbon-sulfur bonds is
Answer:
the order of vibrational frequency is:
C ≡ N > C=N > C=S > S-C
Explanation:
The bond's vibration frequency is determined using the following equation:
[tex]\zeta = \dfrac{1}{2 \pi c}\sqrt{\dfrac{k}{\mu}}[/tex]
where;
reduced mass[tex]\mu = \dfrac{m_1m_2}{m_1+m_2}[/tex]
velcoity of light = c
force constant = k
The frequency of vibration, on the other hand, is inversely proportional to the atom's mass, because the heavier the atom, the lower the frequency.
In addition, the value of a bond's stretching frequency rises as the bond's intensity rises. As a result, the frequency is as follows:
triple > double > single
The reduced mass [tex](\mu)[/tex] of C-N bond.
[tex]\mu = \dfrac{m_1m_2}{m_1+m_2}[/tex]
[tex]\mu = \dfrac{12*14}{12+14} \\ \\ \mu = 6.46[/tex]
The reduced mass of C-S bond;
[tex]\mu = \dfrac{m_1m_2}{m_1+m_2}[/tex]
[tex]\mu = \dfrac{12\times 32}{12+32} \\ \\ \mu = 8.72[/tex]
Thus, the order of vibrational frequency is:
C ≡ N > C=N > C=S > S-C
The size of the orbital is determined by the
The size of the orbital is determined by the blank quantum number, so the size of the orbital blank as this value increases. Therefore, an electron in a blank orbital is closer to the nucleus than is an electron in a blank orbital.
quantum number, so the size of the orbital
The size of the orbital is determined by the blank quantum number, so the size of the orbital blank as this value increases. Therefore, an electron in a blank orbital is closer to the nucleus than is an electron in a blank orbital.
as this value increases. Therefore, an electron in a
The size of the orbital is determined by the blank quantum number, so the size of the orbital blank as this value increases. Therefore, an electron in a blank orbital is closer to the nucleus than is an electron in a blank orbital.
orbital is closer to the nucleus than is an electron in a
The size of the orbital is determined by the blank quantum number, so the size of the orbital blank as this value increases. Therefore, an electron in a blank orbital is closer to the nucleus than is an electron in a blank orbital.
orbital.
orbital.
Answer: The size of the orbital is determined by the principal quantum number, so the size of the orbital increases as this value increases. Therefore, an electron in a (n-1) orbital is closer to the nucleus than is an electron in a 'n' orbital.
Explanation:
In an atom, the position and energy of an electron is described by a set of numbers and these sets are called quantum numbers.
There are four quantum numbers. These are as follows.
1). Principal quantum number - This is denoted by "n" and it determines the size and energy of shell in which electron is present. The value of "n" can be 1, 2, 3, and so on but it can never be equal to zero.
2). Azimuthal quantum number - This is denoted by "l" and it determines the shape of an orbital. For s, p, d and f-shell the values of "n" will be 0, 1, 2, 3. The value of l can vary from -n to +n.
3). Magnetic quantum number - This is denoted by "[tex]m_{l}[/tex]." and it determines the orientation of an orbital. The value of ml can vary from -l to +l.
4). Spin quantum number -- This is denoted by "[tex]m_{s}[/tex]" and it determines the spin of an electron. It is independent of the values of n, l and [tex]m_{l}[/tex].
This means that the size of an orbital is determined by principal quantum number. Lower is the value of 'n' (principal quantum number) more closer will be an electron to the nucleus. Hence, more is the value of 'n' more will be the size of nucleus and vice-versa.
For example, an electron present in a 2s-orbital is closer to the nucleus as compared to the electron present in a 3s-orbital.
Thus, we can conclude that the size of the orbital is determined by the principal quantum number, so the size of the orbital increases as this value increases. Therefore, an electron in a (n-1) orbital is closer to the nucleus than is an electron in a 'n' orbital.