Answer:
The word “organic” refers to how a food is grown. ... However, without preservatives and fewer chemicals than regular produce, you might notice that organic foods taste fresher.
Answer:
The phrase hear, hear seems to have come into existence as an abbreviation of the phrase hear him, hear him, which was well-established in Parliament in the late seventeenth century. ... When you say hear, hear, you are in fact saying that you agree with something another person has just said.
Explanation:
hope it's help you
Use the solubility generalizations on the information page to predict if one or more precipitates will form when aqueous solutions of zinc chloride (ZnCl2) and sodium carbonate (Na2CO3) are mixed. Write the formula of any precipitate that could form.
Answer: The formula for the precipitate formed is [tex]ZnCO_3[/tex]
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation when aqueous solutions of zinc chloride and sodium carbonate are mixed:
[tex]ZnCl_2(aq)+Na_2CO_3(aq)\rightarrow ZnCO_3(s)+2NaCl(aq)[/tex]
By definition, a(n) _______acid is any species that can donate a proton. Ammonia has a proton bonded to nitrogen, so ammonia can be an base (although a very weak one). A(n)___________ base is a proton acceptor, that is, it must have a pair of electrons to share with a proton. In theory, any atom with an unshared electron pair can be a________ pair so ammonia is a_______ proton; instead, it acts as a base and pulls a proton from water to a small extent. base The nitrogen in ammonia has an unshared electron In water, ammonia is too weak an ______-to give up its
Answer:
A Brønsted-Lowry acid.
A Brønsted-Lowry base.
Ammonia is an acceptor of proton.
Explanation:
A Brønsted-Lowry acid is any atom that can donate a proton (H +) to another atom or molecule whereas Brønsted-Lowry base is any species that can accept a proton from another atom or molecule or in other words, a Brønsted-Lowry acid is a proton donor, while on the other hand, a Brønsted-Lowry base is a proton acceptor. The ammonia molecule accepts the hydrogen ion is considered as the Brønsted-Lowry base.
Which of the following would NOT be a suitable solvent for organolithium and organomagnesium reagents?
a. CH3OCH2CH2OCH3
b. CH3CH2OH
c. THF (tetrahydrofuran)
d. CH3CH2OCH2CH3
Answer:
b
Explanation:
it could also be a, c, or d
Titanium(IV) chloride decomposes to form titanium and chlorine, like this:
TiCl4(l) → Ti(s)+ 2Cl2(g)
At a certain temperature, a chemist finds that a reaction vessel containing a mixture of titanium(IV) chloride, titanium, and chlorine at equilibrium has the following composition:
Compound Amount
TiCl4 4.18g
Ti 1.32g
Cl2 1.08g
Required:
Calculate the value of the equilibrium constant for this reaction.
The full question is shown in the image attached to this answer
Answer:
6.2 * 10^-3
Explanation:
The reaction at equilibrium is as follows;
TiCl4(l) → Ti(s)+ 2Cl2(g)
We have to obtain the concentration of chlorine gas as follows;
[Cl2] = 1.08/70.91 g/mol × 5.2 L
[Cl2] = 0.079 M
Kc = [Cl2]^2
Kc = [ 0.079]^2
Kc = 6.2 * 10^-3
does warm air or cool air hold more humidity.
Answer:
warm
Explanation:
(04.02 LC)
During photosynthesis, water and carbon dioxide become glucose and oxygen.
True
False
Answer:
true............,....
Answer:False
Explanation:
This statement is false. Correct statement: Photosynthesis produces glucose and oxygen. ... In this process, plants produce glucose and oxygen from carbon dioxide and water in the presence of sunlight. Photosynthesis converts light energy into chemical energy.
Stoichiometric relationship
1. How many moles of oxygen will be produced from the decomposition of 3 moles of KCIO3?
Balanced Equation: 2 KCIO3 ⇒ 2 KCl + 3 O2
3 mol KClO3 x [tex]\frac{3 mol O2}{2 mol KClO3}[/tex] = 4.5 mol O2
A cough syrup has a density of 1.20 g/mL. A doctor orders 48.0 of the syrup for a sick child. How many teaspoons will you administer to the child
Answer:
because I want to save life
Fred is about to order a stack of four pancakes with butter and syrup, but he wonders how much he would need to exercise to burn off the Calories from it. He pulls out his cell phone and finds the nutritional information for the stack of pancakes. He notes that a serving has 181g of carbohydrates, 27g of fat, and 16g of protein. Now, he has to convert these values into Calories.
Running at a pace of 8 minutes per mile burns 14 Calories/minute. How many minutes would he have to run at an 8 minutes per mile pace to bum off the Calories from the stack of pancakes?
Answer:
The correct answer is - 73.64 minutes.
Explanation:
We know that each gram of protein and carbohydrate produces 4 calories of energy whereas fat produces 9 cal energy per gram.
So, the Calories from carbohydrates
= 181 ×4
= 724 Cal
and, 27 g fat produces = 27 × 9 = 243 Cal
and, 16 g protien = 16 × 4 = 64 Cal
so the total energy will be - 243+ 724+ 64 = 1031 Cal
Thus, the time Fred need to run = 1031/14 =73.64 min
In determining the energy of activation, why was it prudent to run the slowest trial done at room temperature in the hot water bath and the fastest trial done at room temperature in the cold water bath?
Answer:In determining the energy of activation, why was it prudent to run the slowest trial done at room temperature in the hot water bath and the fastest trial done at room temperature in the cold water bath?
Explanation:
name the following compounds TeF4
Answer:
Tellurium Fluoride
Explanation:
who is the father of phycis
Galileo Galilei
hope it helps you
Answer:
Galileo Galilei is the father of Physics
I hope it helps ❤❤
. Which state of matter has a defined volume but no defined shape?
HELPPPP PLEASE FAST
Answer:
liquid
Explanation:
it's not plasma, solid, or gas
so I think liquid
According to the ideal gas law, what happens to the volume of a gas when the pressure doubles (all else held constant)?
A tank contains 10 liters of pure water. A solution of an unknown, but constant concentration of salt is flowing in at 0.5 liters per minute. The water is mixed well and drained at 1 liter per minute. After 20 minutes there are 10 grams of salt in the tank. (i) Give an adequate mathematical model for this scenario. Explain what each of your variables means. (ii) What is the concentration of the incoming salt solution
Answer:
i) ∴∫[tex]\frac{dA}{A}[/tex] = ∫ [tex]\frac{-1}{10} dt[/tex] ------ ( 1 )
ii) C = 4.303
Explanation:
Given data:
water in tank = 10 liters
concentration of salt flowing in = 0.5 liters/min
10 grams of salt is left in tank after 20 minutes
mixed water is drained at 1 liter per minute
i) Adequate mathematical model for the scenario
lets assume ; A( t ) amount of salt after t minute
A( t ) = 10grams where t = 20 minutes
differentiate A(t)
dA / dt = ( rate in ) - ( rate out )
= 0.5 * 0 - A/10
∴∫[tex]\frac{dA}{A}[/tex] = ∫ [tex]\frac{-1}{10} dt[/tex] ------ ( 1 )
ii) hence; In A = [tex]\frac{-1}{10} t + C[/tex] ----- ( 2 )
at t = 20 , A = 10grams
find C = In 10 + 2
= 2.303 + 2 = 4.303
back to ( 2 )
In A = [tex]\frac{-t}{10} + 4.303[/tex]
∴ A = e [tex]\frac{-t}{10} + 4.303[/tex]
Iron-59 which is used to diagnose anaemia has a half life of 45days, what fraction of it is left in 90 days
Answer:
0.25 of the original
Explanation:
(0.5)^(90/45)
The fraction of iron-59 after 90 days is 0.25.
Iron-59 decays following first-order kinetics. Given the half-life ([tex]t_{1/2}[/tex]) of 45 days, we can calculate the rate constant (k) using the following expression.
[tex]k = \frac{ln2}{t_{1/2}} =\frac{ln2}{45day} = 0.015 d^{-1}[/tex]
For first-order kinetics, we can find the fraction of Fe ([Fe]/[Fe]₀) after and an elapsed time (t) of 90 days, using the following equation.
[tex]\frac{[Fe]}{[Fe]_0} =e^{-k \times t } = e^{-0.015 d^{-1} \times 90 d } \approx 0,25[/tex]
The fraction of iron-59 after 90 days is 0.25.
You can learn more about kinetics here:
https://brainly.com/question/2284525
Look at sample problem 19.5 in the 8th ed Silberberg book. Write the ion-product expression at equilibrium for each compound: How to enter the correct answer: e.g. silver sulfate (Ag2SO4) enter this: {Ag+}2{SO42-} don't enter spaces, use square brackets [] not{}or () for concentration and don't worry about subscripting or superscripting
(1) magnesium carbonate
(2) calcium phosphate
(3) silver sulfide
Answer:
See explanation
Explanation:
The term ion product is an expression that does not necessarily reflect equilibrium conditions which can be used to determine the concentration of ions in a solution of the stated substance. As a matter of fact, the ion product is different from the solubility product which reflects equilibrium conditions.
The ion product of the following substances are shown below;
magnesium carbonate - MgCO3
MgCO3(aq) -------> [Mg^2+] [CO3^2-]
calcium phosphate - Ca3(PO4)2
Ca3(PO4)2(aq) --------> [Ca^2+]^3 [PO4^3-]^2
silver sulfide - Ag2S
Ag2S(aq) --------> [Ag^+]^2 [S^2-]
Empirical formula for S3O9
Answer:
* The empirical formula of a compound shows the ratio of elements present in a compound
* The molecular formula of a compound shows how many atoms of each element are present in a molecule of a compound.
Example: the compound butene has a molecular formula of C4H8. The empirical formula
of butene is CH2 because there is a 1:2 ratio of carbon atoms to hydrogen atoms.
Help! I’ll give brainliest if u get it right!
Answer:
That is the Atomic mass
Explanation:
The element symbol is S, Element name is sulfur, and
Atomic number is 16
Methyl isocyanate, shown as resonance structure 1, can also be represented by other resonance structures. Draw the next most important resonance contributor. Then add curved arrows to each structure to show delocalization of electron pairs to form the other structure.
Include lone pairs of electrons, formal charges, and hydrogen atoms. You can add condensed hydrogens using the More menu, selecting +H and clicking on the carbon as many times as needed.
Solution :
Structure I
The formal charge on both Carbon (C) atom is = 4 valance [tex]$e^-$[/tex] - bonds = 0
Formal charge (O) = 6 V.E - 2 bonds - 4 non bonding electrons = 0
Formal charge on (N) = 5 V.E - 3 bonds - 2 non bonding electrons = 0
F.C. on H = 1 V.E. - 1 bond = 0
Overall charge on the molecule = 0 charge
Structure II
Formal charge on both C atom = 4 valence [tex]$e^-$[/tex] - 4 bonds = 0
Formal charge (O) = 6 V.E. - 1 bonds - 6 non bonding electrons = -1 charge
Formal charge on (N) = 5 V.E. - 4bonds - 0 non bonding electrons = +1 charge
F.C on H = 1 V.E. - 1 bond = 0
Overall charge on the molecule = +1 -1
= 0 charge
how can i balance Na + Ca2+ --> Ca + Na+
Answer:
[tex]2Na + Ca^{2+} \rightarrow Ca + 2Na^+[/tex]
Explanation:
Hello!
In this case, since this a reaction in which the oxidation state of the metals is changing, we need to apply a redox method for which:
[tex]Na\rightarrow Na^++e^-\\\\Ca^{2+}\rightarrow Ca+2e^-\\\\\\2Na\rightarrow 2Na^++2e^-\\\\Ca^{2+}\rightarrow Ca+2e^-[/tex]
Thus, the result is:
[tex]2Na + Ca^{2+} \rightarrow Ca + 2Na^+[/tex]
Regards!
A chemist titrates 190.0 mL of a 0.8125 M ammonia (NH) solution with 0.3733 M HCl solution at 25 °C. Calculate the pH at equivalence. The pK, of
ammonia is 4.75.
Round your answer to 2 decimal places.
Note for advanced students: you may assume the total volume of the solution equals the initial volume plus the volume of HCl solution added.
pH ?
Answer:
Approximately [tex]4.92[/tex].
Explanation:
Initial volume of the solution: [tex]V = 190.0\; \rm mL = 0.1900\; \rm L[/tex].
Initial quantity of [tex]\rm NH_3[/tex]:
[tex]\begin{aligned} n({\rm NH_3}) &= c({\rm NH_3}) \cdot V({\rm NH_3}) \\ &= 0.3733\; \rm mol \cdot L^{-1} \times 0.1900\; \rm L \\ &\approx 0.154375\; \rm mol\end{aligned}[/tex].
Ammonia [tex]\rm NH_3[/tex] reacts with hydrochloric [tex]\rm HCl[/tex] acid at a one-to-one ratio:
[tex]\rm NH_3 + HCl \to NH_4 Cl[/tex].
Hence, approximately [tex]n({\rm HCl}) = 0.154375\; \rm mol[/tex] of [tex]\rm HCl\![/tex] molecules would be required to exactly react with the [tex]\rm NH_3\![/tex] in the original solution and hence reach the equivalence point of this titration.
Calculate the volume of that [tex]0.3733\; \rm mol \cdot L^{-1}[/tex] [tex]\rm HCl[/tex] solution required for reaching the equivalence point of this titration:
[tex]\begin{aligned}V({\rm HCl}) &= \frac{n({\rm HCl})}{c({\rm HCl})} \\ &\approx \frac{0.154375\; \rm mol}{0.3733\; \rm mol \cdot L^{-1}} \approx 0.413541\; \rm L\end{aligned}[/tex].
Hence, by the assumption stated in the question, the volume of the solution at the equivalence point would be approximately [tex]0.413541\; \rm L + 0.1900\; \rm L \approx 0.6035\; \rm L[/tex].
If no hydrolysis took place, [tex]0.154375\; \rm mol[/tex] of [tex]\rm NH_4 Cl[/tex] would be produced. Because [tex]\rm NH_4 Cl\![/tex] is a soluble salt, the solution would contain [tex]0.154375\; \rm mol\![/tex] of [tex]\rm {NH_4}^{+}[/tex] ions. The concentration of [tex]\rm {NH_4}^{+}\![/tex] would be approximately:
[tex]\begin{aligned}c({\rm {NH_4}^{+}}) &= \frac{n({\rm {NH_4}^{+}})}{V({\rm {NH_4}^{+}})}\\ &\approx \frac{0.154375\; \rm mol}{0.6035\; \rm L} \approx 0.255782\; \rm mol \cdot L^{-1}\end{aligned}[/tex].
However, because [tex]\rm NH_3 \cdot H_2O[/tex] is a weak base, its conjugate [tex]\rm {NH_4}^{+}[/tex] would be a weak base.
[tex]\begin{aligned}pK_{\rm a}({{\rm NH_4}}^{+}) &= pK_{\rm w} - pK_{\rm b}({\rm NH_3})\\ &\approx 13.99 - 4.75 = 9.25\end{aligned}[/tex].
Hence, the following reversible reaction would be take place in the solution at the equivalence point:
[tex]\rm {NH_4}^{+} \rightleftharpoons NH_3 + H^{+}[/tex].
Let [tex]x\; \rm mol \cdot L^{-1}[/tex] be the increase in the concentration of [tex]\rm H^{+}[/tex] in this solution because of this reversible reaction. (Notice that [tex]x \ge 0[/tex].) Construct the following [tex]\text{RICE}[/tex] table:
[tex]\begin{array}{c|ccccc} \textbf{R}& \rm {\rm NH_4}^{+} & \rightleftharpoons & {\rm NH_3}& + & {\rm H}^{+}\\ \textbf{I} & 0.255782 \; \rm M \\ \textbf{C} & -x \;\rm M & & + x\;\rm M & & + x\; \rm M \\ \textbf{E} & (0.255782 - x)\; \rm M & & x\; \rm M & & x\; \rm M\end{array}[/tex].
Thus, at equilibrium:
Concentration of the weak acid: [tex][{\rm {NH_4}^{+}}] \approx (0.255782 - x) \; \rm M[/tex].Concentration of the conjugate of the weak acid: [tex][{\rm NH_3}] = x\; \rm M[/tex].Concentration of [tex]\rm H^{+}[/tex]: [tex][{\rm {H}^{+}}] \approx x\; \rm M[/tex].[tex]\displaystyle \frac{[{\rm NH_3}] \cdot [{\rm H^{+}}]}{[{ \rm {NH_4}^{+}}]} = 10^{pK_\text{a}({\rm {NH_4}^{+}})}[/tex].
[tex]\displaystyle \frac{x^2}{0.255782 - x} \approx 10^{-9.25}[/tex]
Solve for [tex]x[/tex]. (Notice that the value of [tex]x\![/tex] is likely to be much smaller than [tex]0.255782[/tex]. Hence, the denominator on the left-hand side [tex](0.255782 - x) \approx 0.255782[/tex].)
[tex]x \approx 1.19929 \times 10^{-5}[/tex].
Hence, the concentration of [tex]\rm H^{+}[/tex] at the equivalence point of this titration would be approximately [tex]1.19929 \times 10^{-5}\; \rm M[/tex].
Hence, the [tex]pH[/tex] at the equivalence point of this titration would be:
[tex]\begin{aligned}pH &= -\log_{10}[{\rm {H}^{+}}] \\ &\approx -\log_{10} \left(1.19929 \times 10^{-5}\right) \approx 4.92\end{aligned}[/tex].
Observe: Click Reset. Select the Gas collection setup. Chemists use this apparatus to collect any gases produced in the reaction. From the reaction flask, gases travel through a long tube and into a cylinder of water. As gases bubble into the cylinder, the water is displaced (removed) until the cylinder is filled with gas. Was any gas produced in the reaction? How do you know? I WILL GIVE POINTS AND BRAINLIEST IF YOU ANSWER CORRECTLY. THANK YOU :)
Answer:
Due to displacement of water.
Explanation:
If the water is displaced in the cylinder it means that the gas is produced in the reaction while on the other hand, if the water is not displaced in the cylinder so it means that the reaction does not produces any gas yet. So we can say that the displacement of waters indicates or shows us whether the gas is produced in the reaction or not.
Based on the following equation, how many moles of hydrochloric acid (HCl)are needed to react with 0.44 moles of potassium
permanganate (KMnO4)?
2KMnO4 + 8HCI - 3Cl2 + 2MnO2 + 4H2O + 2KCI
Answer:
1.76 moles of HCl.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2KMnO₄ + 8HCl —> 3Cl₂ + 2MnO₂ + 4H₂O + 2KCl
From the balanced equation above,
2 moles of KMnO₄ reacted with 8 moles of HCl.
Finally, we shall determine the number of mole of HCl needed to react with 0.44 moles of KMnO₄. This can be obtained as follow:
From the balanced equation above,
2 moles of KMnO₄ reacted with 8 moles of HCl.
Therefore, 0.44 moles of KMnO₄ will react with = (0.44 × 8)/2 = 1.76 moles of HCl.
Thus, 1.76 moles of HCl is needed for the reaction.
The molecular-orbital model for Ge shows it to be:_______.
A) a conductor, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large.
B) an insulator, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large.
C) a semiconductor, because the gap between the filled lower and empty higher energy bands is relatively small.
D) a semiconductor, because the gap between the filled lower and empty higher energy bands is large.
E) a conductor, because its lower energy band orbitals are only partially filled.
Answer:
Option C
Explanation:
Pure germanium is a bad conductors of electricity. It is so because its valence band is full and its outer electrons are attached through covalent bond is a diamond like framework. In metallic sense, it is neither a conductor nor an insulator but a semiconductor. It has a small band gap of 0.7eV.
Hence, option C is correct
3. Which state of matter has a defined shape?
HELP FAST
Answer:
Solid state of matter has a definite shapeThe answer to this is solids!
How many moles of potassium sulfate are present in a sample that weighs 45.8g?
I do not understand how to solve this please help
Answer:
0.263 mol
Explanation:
K2SO4 - potassium sulfate
Molar mass (K2SO4) = 2*39.0983 + 32.065 + 4*15.9994 =
= 174.2592≈174.26 g/mol
45.8 g * 1 mol/174.26 g = 0.263 mol
write down four fuctions of water learned in life sciences class
Answer:
See explanation
Explanation:
Water is a polar solvent and is also called a universal solvent because of its ability to dissolve several substances especially in the body.
The functions of water learned in the life sciences class include;
1. Water is the medium for biochemical reactions
2. Most substances in the body are transported from place to place by water.
3. Water acts a solvent for many biologically important substances in the body.
4. Water is necessary in helping animals to regulate their body temperature.
A biochemist prepares a 1 L solution using 12.1 g of Tris Buffer. The final concentration is 0.1 M. What is the MW of Tris Buffer?
Answer: The molecular weight of tris buffer is 121 g/mol
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of tris buffer = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{12.1g}{Mg/mol}[/tex]
Now put all the given values in the formula of molality, we get
[tex]0.1=\frac{12.1g}{Mg/mol\times 1L}[/tex]
[tex]M=121g/mol[/tex]
Therefore, the molecular weight of tris buffer is 121 g/mol
What are the main sources of outdoor air pollution and how do they cause smog?
Answer:
The common sources of outdoor air pollution are emissions caused by combustion processes from motor vehicles, solid fuel burning and industry. Other pollution sources include smoke from bushfires, windblown dust, and biogenic emissions from vegetation (pollen and mold spores).
smog is produced when sunlight reacts with nitrogen oxides in the atmosphere. Nitrogen oxides come from car exhaust, coal power plants, and factory emissions. When sunlight hits these chemicals, they form airborne particles and ground-level ozone—or smog.