Answer:
a lipped cylindrical glass container for laboratory use
Explanation:
Tryptophan, an essential amino acid, is important in the synthesis of the neurotransmitter serotonin in the body.
a. True
b. False
Answer:
B porque si :) y eso Jsksjs
Answer:A
Because it's an amino acid and all amino acids are key to any part of your body.
When 125 mL of 0.150 M Pb(NO3)2 is mixed with 145 mL of 0.200 M KBr, 4.92 g of PbBr2 is collected. Calculate the percent yield.
Answer:
Y = 92.5 %
Explanation:
Hello there!
In this case, since the reaction between lead (II) nitrate and potassium bromide is:
[tex]Pb(NO_3)_2+2KBr\rightarrow PbBr_2+2KNO_3[/tex]
Exhibits a 1:2 mole ratio of the former to the later, we can calculate the moles of lead (II) bromide product to figure out the limiting reactant:
[tex]0.125L*0.150\frac{molPb(NO_3)_2}{L} *\frac{1molPbBr_2}{1molPb(NO_3)_2} =0.01875molPbBr_2\\\\0.145L*0.200\frac{molKBr}{L} *\frac{1molPbBr_2}{2molKBr} =0.0145molPbBr_2[/tex]
Thus, the limiting reactant is the KBr as it yields the fewest moles of PbBr2 product. Afterwards, we calculate the mass of product by using its molar mass:
[tex]0.0145molPbBr_2*\frac{367.01gPbBr_2}{1molPbBr_2} =5.32gPbBr_2[/tex]
And the resulting percent yield:
[tex]Y=\frac{4.92g}{5.32g} *100\%\\\\Y=92.5\%[/tex]
Regards!
The molecular mass of a compound is determined to be 180.0 and a composition of 60.0% C and 4.48% H and the remainder is Oxygen. What is the molecular formula of the compound.
Answer:
18%.0
Explanation:
hipe it helps
pa brainlist
The temperature of a sample of silver increased by 23.8 °C
when 261 J of heat was applied.
What is the mass of the sample?
Answer:
46.67 g
Explanation:
From the question given above, the following data were obtained:
Change in temperature (ΔT) = 23.8 °C
Heat (Q) = 261 J
Specific heat capacity (C) of silver = 0.235 J/gºC
Mass of silver (M) =?
The mass of the sample of silver can be obtained as follow:
Q = MCΔT
261 = M × 0.235 × 23.8
261 = M × 5.593
Divide both side by 5.593
M = 261 / 5.593
M = 46.67 g
Thus, the mass of the sample of silver is 46.67 g
Calculate the mass in grams of 24.5 mL of diethyl ether, an anesthetic that has a density of 0.713 g/mL. Round your answer to the tenth's place.
Answer:
17.48
Explanation:
mass=density×volume
= 0.713g/ml × 24.5 ml
= 17.4685
≈ 17.47
In what form is energy that is NOT used for life processes released from living things?
1. Thermal energy
2. Chemical energy
3. Light energy
4. Sound energy
Answer:
Correct answer would be Option 2, Chemical Energy
Hope this helps!
Hydrogen gas was cooled from 150 K to 50 K. Its new volume (V2) is 75 mL. What was its original volume (V1)?
Explanation:
57.3ml
we use Charles's law
to solve the question
Answer:
[tex]\boxed {\boxed {\sf 225 \ mL}}[/tex]
Explanation:
The temperature and volume of the gas are changing, so we use Charles's Law. This states the temperature of a gas is directly proportional to the volume of a gas. The formula is:
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]
The original volume is unknown. The new volume is 75 milliliters.
The gas is cooled from 150 Kelvin to 50 Kelvin, so the original temperature is 150 K and the new temperature is 50 K.
We know that:
T₁= 150 K V₂= 75 mL T₂= 50 KSubstitute the values into the formula.
[tex]\frac {V_1}{150 \ K}=\frac{ 75 \ mL}{50 \ K}[/tex]
Since we are solving for the original volume, we must isolate the variable V₁.
It is being divided by 150 K. The inverse of division is multiplication, so we multiply both sides by 150 K.
[tex]150 \ K *\frac {V_1}{150 \ K}=\frac{ 75 \ mL}{50 \ K}* 150 \ K[/tex]
[tex]V_1=\frac{ 75 \ mL}{50 \ K}* 150 \ K[/tex]
The units of Kelvin (K) cancel.
[tex]V_1= \frac{ 75 \ mL}{50 }* 150[/tex]
[tex]V_1=1.5 * 150 \ mL[/tex]
[tex]V_1= 225 \ mL[/tex]
The original volume is 225 milliliters.
A rock was weighed on a balance and found to have a mass of 34.56 grams. It was placed into water that was in a graduated cylinder. Before the rock was dropped into the water the water level was 22.7 mL. The addition of the solid object caused the water level to rise to 28.1 mL. What is the density of the rock?
Answer:
5 and the rest are all set to the same date on your list as the other one to get you a list on for a your special first year week and with a special holiday party holiday
Explanation:
Sorry desperate for points
Use the graph to calculate the instantaneous rate of formation of HBr at 50 s
Express your answer using one significant figure.
Answer: The instantaneous rate of formation of HBr at 50 s is [tex]1.4\times 10^{-2}M/s[/tex]
Explanation:
From the graph,
Initial rate of the [tex]Br_2[/tex] = 1.0 M
Time when the concentration of [tex]Br_2[/tex] is 0.5 M (half the concentration ) = 60 sec
For first order reaction:
Calculating rate constant for first order reaction using half life:
[tex]t_{1/2}=\frac{0.693}{k}[/tex] .....(1)
[tex]t_{1/2}[/tex] = half life period = 60 s
k = rate constant = ?
Putting values in equation 1:
[tex]k=\frac{0.693}{60s}\\\\k=0.01155s^{-1}[/tex]
For the given chemical reaction:
[tex]H_2(g)+Br_2(g)\rightarrow 2HBr(g)[/tex]
Rate of the reaction = [tex]-\frac{\Delta [Br_2]}{\Delta t}=\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}[/tex]
Negative sign represents the disappearance of the reactants
From the above expression:
[tex]k[Br_2]=-\frac{\Delta [Br_2]}{\Delta t}=\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}[/tex]
At 50 seconds, [tex][Br_2]=0.6 M[/tex]
Plugging values in above expression, we get:
[tex]\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}=0.01155\times 0.6\\\\\frac{\Delta [HBr]}{\Delta t}=2\times 0.01155\times 0.6=0.01386=1.4\times 10^{-2}M/s[/tex]
Hence, the instantaneous rate of formation of HBr at 50 s is [tex]1.4\times 10^{-2}M/s[/tex]
Which substance has Delta.Hf defined as 0 kJ/mol? H2O (s) Ne (l) F2 (g) CO2 (g)
Answer:
F2 (g)
Explanation:
Edg 2021
Answer:
F2 g
Explanation:
What should the coefficient for the diatomic oxygen (O2) be when this equation is correctly balanced
3
And then for Fe it should be 4 and for the products it should be 2!!
Rank the compounds below in order of decreasing base strength.
a. HPO4^2-
b. NH3
c. NO2
d. SO4^2-
Answer:
c. NO2
b. NH3
d. SO4 ^2 -
a. HPO4 ^ 2 -
Explanation:
Acid is a compound which ionizes to produce hydrogen ions. The Ph value for acid is below 7. Base is a compound which ionizes to produce hydroxide ions. The Ph value for base is above 7. The Conjugate base accepts a proton or releases a hydrogen ion.
an experiment is carried out to determine the formula of an oxide of mercury. the oxide is a red solid. it decomposed into its elements when heated at room temperature and pressure (r.t.p.). // mass of oxide of mercury: 2.16g // volume of oxygen collected at r.t.p.: 120cm³ // what is the mass of mercury produced?
Answer:
Mass of mercury produced = 2.00 g
Explanation:
At room temperature and pressure, the temperature T = 25° C or 298.15 K while the pressure = 1 atmosphere or 760 mmHg.
Mass of oxide of mercury decomposed at room temperature and pressure = 2.16 g
Volume of oxygen produced = 120 cm³ or 0.12 dm³
One mole of any gas has a volume of 24 dm³ at room temperature and pressure.
Therefore, number of moles of oxygen produced = 0.12 dm³ / 24 dm³/mol = 0.005 moles
Mass of oxygen produced = number of moles × molar mass
Molar mass of oxygen = 32 g/mol
Mass of oxygen produced = 0.005 moles × 32 g/mol = 0.16 g
Thus, mass of mercury produced = mass of mercury oxide decomposed - mass of oxygen produced
Mass of mercury produced = 2.16 g - 0.16 g
Mass of mercury produced = 2.00 g
How to change τhe color of silver mercury to red???
Answer: This is the hue of mercury if you're looking for it. Mercury reacts with sulphur to generate a crimson hue. In the past, they always used a thermometer.
Explanation: However, due of its toxicity, individuals have switched to using alcohol in glass thermometers, which work similarly to mercury thermometers.
hope this helped best of luck mate! :) if this helped make sure to mark me Brainliest!
What is the Kc expression for this reaction?
2 NO(g) + O2(g) ⇌ 2 NO2(g)
a)Kc = [NO2]2 / [NO]2 [O2]
b)Kc = [NO]2 [O2] / [NO2]2
c)Kc = [NO]2 [O2] [NO2]2
d)Kc = [NO2]2 / [NO]2 + [O2]
Answer:
D
Explanation:
because product are at the top and reactant are at the bottom also it to the power of the moles in front e.g 2NO it will be to the power of 2 in this case.
hope it make sense :)
The relationship between the volume and mass of an element is
Answer:
Density
Explanation:
The mass of an element is the average weight that the isotope of the particular element contains. Its characteristic indicates the amount of substance present in an element.
However, the volume of an element on the other hand is the mole of an element that is contained in a room temperature.
The relation joining both the mass and volume of an element is density.
This is because density showcase the relationship between the mass of an element to space in occupies in terms of volume.
It is given by the formula:
Density = mass/volume
Explain your understanding of functional group in organic chemistry
Answer:
A functional group in organic chemistry is an atom or group of atoms that is responsible for the specific properties of an organic compound. Some examples of functional groups include alcohols, alkyl halides, ethers, aldehydes, ketones, amines, carboxylic acids, and esters.
Functional groups also play an important part in organic compound nomenclature; combining the names of the functional groups with the names of the parent organic compounds provides a way to distinguish compounds.
The atoms of a functional group are linked together and to the rest of the compound by covalent bonds. The first carbon atom that attaches to the functional group is referred to as the alpha carbon; the second, the beta carbon; the third, the gamma carbon, etc. Similarly, a functional group can be referred to as primary, secondary, or tertiary, depending on if it is attached to one, two, or three carbon atoms.
What is the molarity if 6664 grams of boron iodide is dissolved in 5.25 liters of water?
Answer:
3.24 mol/L
Explanation:
Given that:
mass of Boron triiodide = 6664 grams
molar mass of BI_3 = 391.52 g/mol
Recall that:
number of moles = mass/molar mass
∴
number of moles = 6664 g /391.52 g/mol
number of moles = 17.02 mol
Also;
Molarity = moles for solute/liter for solution
= 17.02 mol/5.25 L
= 3.24 mol/L
rank in order the strongest to the weakest acid cbr3cooh, ch3cooh and ccl3cooh
Answer: Rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] > [tex]CBr_{3}COOH[/tex] > [tex]CH_{3}COOH[/tex].
Explanation:
More readily a substance is able to donate a hydrogen ion more will be its acidic strength. Hence, stronger will be the acid.
More is the electronegativity of atoms attached to the acid more easily it will donate a proton. Hence, more will be its acidic strength.
Chlorine is more electronegative in nature as compared to bromine. So,
[tex]CCl_{3}COOH[/tex] is more acidic than [tex]CBr_{3}COOH[/tex].
Since there is no electronegative group attached to [tex]CH_{3}COOH[/tex] so it is least acidic than [tex]CCl_{3}COOH[/tex] and [tex]CBr_{3}COOH[/tex].
Thus, we can conclude that rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] > [tex]CBr_{3}COOH[/tex] > [tex]CH_{3}COOH[/tex].
Please help me complete this, it’s my last chance
Protons: charge: +1 // mass: 1 // location: nucleus
Neutrons: charge: 0// mass: 1 // location: nucleus
Electrons: charge: -1// mass: 0// location: orbitals
You deserve 0.72G of potassium chloride (KCI) in 600 ml of water. What is the molarity of the solution ?
Answer:
0.016 M
Explanation:
Molarity refers to the molar concentration of a solution and it can be calculated using the formula below:
Molarity (M) = number of moles (n) ÷ volume (V)
According to this question, the mass of KCl was given to be 0.72 grams and the volume of water as 600 mL.
Using mole = mass/molar mass to convert mass of KCl to moles
Molar mass of KCl = 39 + 35.5 = 74.5g/mol
mole = 0.72g ÷ 74.5g/mol
mole = 0.00966mol
Volume of water = 600mL = 600/1000 = 0.600L
Molarity, M = 0.00966 ÷ 0.600
Molarity of KCl solution = 0.016 M
briefly describe the action of hardwater with soap
Answer:
The correct answer is - hard water reacts to form the calcium or magnesium salt of the organic acid of the soap.
Explanation:
Soaps are made up of fatty acids or oils by treating with strong alkali and are salts of sodium and potassium. Hard water, on the other hand, has a high concentration of minerals in comparison to soft water. When hard water and soap are mixed together the salts of the minerals like Ca2+ and Mg2+ ions present in hard water react with fatty acids of the soap.
The sodium salts are changed to the salts of calcium and magnesium which are precipitated to an insoluble substance. The insoluble salts of the calcium or magnesium dirt stick on the clothes thus cleaning ability of soap is reduced.
electron affinity of lithium is -60 whereas of cesium is -45.this trend is due to... plz give me accurate answer
Which hydrocarbon is saturated?
A)
heptyne
B)
butane
C)
propene
D)
ethyne
Read the given equation:
NH + HCI - NH4ACI
Which of the following is true about the equation?
NH3 is the acid and NH4Cl is the salt.
NH3 is the base and NH4Cl is the salt.
HCI is the acid and NH3 is the salt.
HCl is the base and NH3 is the salt.
Answer:
NH3 is the base and NH4Cl is the salt.
Explanation:
Hello there!
In this case, according to the given information, it is possible for us to rewrite the chemical equation and thus obtain:
[tex]NH_3+HCl\rightarrow NH_4Cl[/tex]
Whereas it is possible to notice that ammonia, NH3, received the hydrogen ions from HCl to form NH4 ions and Cl ions; in such a way, we infer that NH3 is the base and NH4Cl is the salt.
Regards!
Answer:
NH3 is the base and NH4Cl is the salt
Explanation:
so de fanga gu se si gage humang we sapa shata phoni we heo sang pai
Answer:
Which language is this???
Order the following chemicals from lowest to highest melting point.
Tungsten
Copper (II) chloride
• Caffeine
• Lead
• Sodium chloride
• Silver
Answer
• Silver
• copper
A sample of 0.2140 g of an unkown substance monoprotic acid was dissolved in 25.0 mL of water and titrated with 0.950 M NaOH. The acid required 27.4 mL of base to reach the equivalence point. After 15.0 mL of base had been added in the titration, the pH was found to be 6.50. What is the Ka for the unknown acid?
Solution :
The equation is :
[tex]$HA (aq) + NaOH(aq) \rightleftharpoons NaA(aq) + H_2O(l)$[/tex]
The number of the moles of HA os 0.00285, and the volume is 25 mL.
15 mL of the 0.0950 M NaOH is added.
The total volume of a solution is V = 25 mL + 15 mL = 40 mL
The pH of the solution is 6.50
Calculating the [tex]K_a[/tex] of HA
[tex]$HA(aq) \rightleftharpoons A^-(aq)+H^+$[/tex]
[tex]K_a=\frac{[A^-].[H^+]}{[HA]}[/tex]
Let s calculate the concentration of HA and NaOH
[tex]$[HA] = \frac{^nH_A}{V}$[/tex]
[tex]$=\frac{0.00285 \ mol}{0.04 \ L}$[/tex]
= 0.07125 M
[tex]$[NaOH]= \frac{0.015L \times 0.0950 M}{V}$[/tex]
[tex]$=\frac{0.001425 mol}{0.04L}$[/tex]
= 0.0356 M
[tex]$HA(aq) \ \ + \ \ NaOH(aq) \ \ \rightleftharpoons NaA(aq) \\ + \ \ H_2O(aq)$[/tex]
Initial conc. (M) 0.07125 M 0.0356 M 0 M
Change in conc. (M) -0.0356 M -0.0356 M + 0.0356 M
Equilibrium conc. (M) 0.03565 M 0 M 0.0356 M
Therefore, the concentration of HA and the NaA at the equilibrium are [HA] = 0.03565 M and [NaA]= 0.0356 M
0.0356 M of NaA dissociates completely into 0.0356 M [tex]Na^+[/tex] and 0.0356 M [tex]A^-[/tex]
Now for [tex][H^+][/tex]
[tex]$[H^+] = 10^{-pH}$[/tex]
[tex]$=10^{-6.5}$[/tex]
[tex]$=3.16 \times 10^{-7}$[/tex]
Calculating the value of [tex]K_a[/tex],
[tex]K_a=\frac{[A^-].[H^+]}{[HA]}[/tex]
[tex]$=\frac{0.0356 \times 3.16 \times 10^{-7}}{0.03565}$[/tex]
[tex]$=3.16\times 10^{-7}$[/tex]
Therefore the the value of [tex]K_a[/tex] for the unknown acid is [tex]$3.16\times 10^{-7}$[/tex].
How many moles of electrons must be transferred to plate out 110 g of manganese (MW ~ 55g/mol) from a solution of permanganate (MnO4-)
Answer:
14 mol e⁻
Explanation:
Step 1: Write the balanced half-reaction for the reduction of permanganate to manganese
8 H⁺(aq) + 7 e⁻ + MnO₄⁻(aq) ⇒ Mn(s) + 4 H₂O(l)
Step 2: Calculate the moles corresponding to 110 g of manganese
The molar mass of Mn is 55 g/mol.
110 g × 1 mol/55 g = 2 mol
Step 3: Calculate the number of moles of electrons needed to produce 2 moles of Mn
According to the half-reaction, 7 moles of electrons are required to produce 1 mole of Mn.
2 mol Mn × 7 mol e⁻/1 mol Mn = 14 mol e⁻
You are given a 250 ml sample of HCI and asked to find out what its concentration is. You have a 0 118 M Ca(OH)2 solution and it takes 13.7 ml to
neutralize the acid sample. What is the concentration of the HCI? Show explanation Please help this is urgent
Answer:
The concentration of the acid, HCl is 0.013 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HCl + Ca(OH)₂ —> CaCl₂ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nₐ) = 2
The mole ratio of base, Ca(OH)₂ (n₆) = 1
Finally, we shall determine the molarity of the HCl. This can be obtained as follow:
Volume of acid, HCl (Vₐ) = 250 mL
Molarity of base, Ca(OH)₂ (M₆) = 0.118 M
Volume of base, Ca(OH)₂ (V₆) = 13.7 mL
Molarity of acid, HCl (Mₐ) =?
MₐVₐ / M₆V₆ = nₐ/n₆
Mₐ × 250 / 0.118 × 13.7 = 2/1
Mₐ × 250 / 1.6166 = 2
Cross multiply
Mₐ × 250 = 1.6166 × 2
Mₐ × 250 = 3.2332
Divide both side by side 250
Mₐ = 3.2332 / 250
Mₐ = 0.013 M
Thus, the concentration of the acid, HCl is 0.013 M