What is the difference between Benedict’s test and Barfoeds test?
Answer:
Benedict's test would determine if the sample is a reducing sugar, and Barfoed's test would determine if it is a monosaccharide or disaccharide.
The 4-4-9 system is used to estimate the number of _______ in food. Question 9 options: A) kilojoules B) calories C) joules D) nutritional Calories
Answer: B) calories
Explanation:
The 4-4-9 system is used to estimate the number of calories in food. Under this system, it is assumed that one gram of Protein, one gram of Carbohydrates and one gram of Fats each contribute 4, 4 and 9 calories respectively to the caloric total.
This means that to find out the number of calories in food, multiply the total grams of proteins by 4, the total grams of carbohydrates by 4 and the total grams of Fats by 9 and then add up the results to find out the caloric contribution of Protein, Carbohydrates and Fats.
Answer:
It's not C calories i put that and missed it
Explanation:
Please please help :/
Answer:
eliptical
Explanation:
Calculate the pH and pOH of 500.0 mL of a phosphate solution that is 0.285 M HPO42– and 0.285 M PO43–. (Ka for HPO42- = 4.2x10-13 at 25°C)
Answer: when concentrations of acid and base are same, pH = pKa
PH = 12.38 pOH = 1.62
Explanation: pKa= -log(Ka)= 12.38. PH + pOH = 14.00
The pH of the solution is 12.38 and the pOH of the solution is 1.62.
Using the Henderson Hasselbalch equation;
pH = pKa + log [A-]/[HA]
Where;
pKa = - log Ka = -log[ 4.2x10-13] = 12.38
[A-] = [PO43–] = 0.285 M
[HA] = [HPO42-] = 0.285 M
Substituting values;
pH = 12.38 + [ 0.285 M]/[ 0.285 M]
pH = 12.38
But;
pH + pOH = 14
pOH = 14 - 12.38
pOH = 1.62
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If brainly never existed where would you be right now?
Answer: To be honest I’ll be watching the television or doing interesting and education things like reading books and learning...
Answer:
SLEEPING,NAPPING, LAYING DOWN
Explanation:
How might the population of grasshoppers be affected if the population of owl were to suddenly decrease
Answer:
the population of grasshoppers would rise since there is less owls to eat them.
Explanation:
hope this helps
The percentage composition of a compound expresses the
amount (by weight) of constituent elements in of the
compound
Answer:
The percentage composition of a compound expresses how much of each element is in the compound.
If an element has 6 protons and its mass number is 14, how many neutrons and electrons does it have?
Answer:
8 neutrons and 6 electrons
Explanation:
Mass number= neutrons + protons
14=x+6
x=14-6
x=8
protons=electrons
6 protons=6 electrons
Make a rule: If you knew the number of valence electrons in a nonmetal atom, how would you determine the valence of the element? (Hint: Ignore hydrogen for now.)
AnswMake a rule : If you knew the number of valence electrons in a nonmetal atom, how would you determine the valence of the element? (Hint: Ignore hydrogen for now.) The group number of the element will tell you the amount of valence electrons. there has to be a full octet in order for it to be stable. 7.er:
Explanation:
In addition to Earth, many of the other planets in the Solar System have atmospheres.
O True
O False
the answer is True.
each planet has a significant atmosphere
Answer:
True
Explanation:
bc i know
What reaction type is 1p4+302 = 2p2O3
Answer:
13
Explanation:
How many atoms of H are in 1 mole of NH3
Answer:
Before you use log you have to multiply the answer of 8.66 mol by 6.02⋅1023 by 3 because the answer of 8.66 mol by 6.02⋅1023 gives you the number of ammonia molecules and in each molecules there are 3 hydrogen atoms present.
Explanation:
25 If the all the white mice are selected against in this environment (eaten by predators) what would happen to the gray mice if the environment were to change quickly to favor white mice? A. B. C. The gray mice would all change to white fur quickly and survive because the genetic traits are recessive and therefore still available in the population's genetics. The gray mice would immediately be eaten by the predators in the area and go extinct. The gray mice could still give birth to white mice if the trait remained in their genetic information and the population could produce white fur offspring which over time would succeed and reproduce causing an increase in white mice. The gray mice would have to move and white mice would move into the area causing the two to quickly develop different genetic traits and to evolve into entirely separate species until the two are no longer the same population. D.
Answer: The gray mice would immediately be eaten by the predators in the area and go extinct.
Explanation:
Natural selection is the differential survival of some members of the population of species which have better phenotypic advantage over others. Such members will survive and reproduce. According to the given situation, white mice were the choice of food for predators and the recessive trait of gray color of gray mice was favoring their survival as they may remain undetected by the predators. But the predators were able to detect the gray mice and changed their food preference from white to gray this way predators will consume all the gray mice and they may extinct in future as it is not possible to change the color of the fur from white to gray so quickly. The adaptation and passage of white trait among the members of the population will occur with a gradual change in successive generations of the population.
Identify the kind(s) of intermolecular forces that would occur between the solute and solvent in an acetic acid (which is polar and contains an OHOH group) solution. Check all that apply. Check all that apply. dispersion hydrogen bonding ion-dipole dipole-dipole
Explanation:
The acetic acid is a polar compound. The polar molecules have a positive and negative extreme for this reason they are dipoles. The dipoles can attract other dipoles or ions. So, it can establish ion-dipole and dipole-dipole forces with the solute. In addition, acetic acid has a hydroxyl group that can interact with hydrogens or other very electronegative atoms (oxygen, nitrogen and fluor) forming hydrogen bridge junctions.
Jen and her partner were assigned the Zn/Zn cathode/anode pair which they used to construct their electrolytic cell. They decided to keep the concentration of the corresponding Zn2+ solution constant at 1 M. If Jen ran her cell for 22.8 mins, what current (mA) did she use in order to transfer 9 x 10^-4 moles of electrons?
Answer:
63.2 mA
Explanation:
We all know that:
Current[tex]I = \dfrac{Q}{t}[/tex]
which can be further expressed as:
[tex]I = \dfrac{ne}{t}[/tex]
where;
n = number of electrons
e = charge on electrons
t = time (second)
Then; by replacing the values in the question, we have:
[tex]\dfrac{(9*10^{-4})\times6\times10^{23}\times1.6\times10^{-19}}{22.8\times60}[/tex]
[tex]= 0.06316 A \\ \\ \mathbf{I= 63.2 \ mA}[/tex]
How many liters of nitrogen gas (N₂) are required to produce 7.5 x 10²⁶ molec NH₃ gas with excess of hydrogen gas at STP?
Answer: The volume of nitrogen gas that is required is 13944 L.
Explanation:
Given values:
Number of molecules of ammonia gas = [tex]7.5\times 10^{26}[/tex]
According to the mole concept:
[tex]6.022\times 10^{23}[/tex] number of molecules are present in 1 mole of a compound
So, [tex]7.5\times 10^{26}[/tex] number of molecules will be present in [tex]\frac{1}{6.022\times 10^{23}}\times 7.5\times 10^{26}=1.245\times 10^3 moles[/tex] of ammonia gas
The chemical equation for the formation of ammonia gas follows:
[tex]N_2 (g) + 3H_2(g) \rightarrow 2NH_3(g)[/tex]
According to the stoichiometry of the reaction:
2 moles of ammonia gas are produced from 1 mole of nitrogen gas
So, [tex]1.245\times 10^3[/tex] moles of ammonia gas will be produced from [tex]\frac{1}{2}\times 1.245 \times 10^3=6.225\times 10^2[/tex] moles of nitrogen gas
At STP conditions:
1 mole of a gas occupies 22.4 L of volume
So, [tex]6.225 \times 10^2[/tex] moles of nitrogen gas will occupy [tex]\frac{22.4 L}{1 mol}\times 6.225\times 10^2 moles=13944 L[/tex] of volume
Hence, the volume of nitrogen gas that is required is 13944 L.
how are electrons arranged in molecules of compounds?
Answer:
electrons are always in the outer shell
When an electron moves, it absorbs or produces energy in the form of photons. Electrons surround the nucleus, which is made up of protons and neutrons, and they all form an atom. The exchange or sharing of electrons between atoms is the main cause of chemical bonding.
Hope this helps you :)
How many grams of water can be formed from the reaction of 8.76 grams of H2 with 10.5 liters of O2 (at STP) according to the balanced equation: 2 H2 + O2 --> 2 H2O Express your answer to 3 sig figs. Do NOT include units!
Answer:
16.9g of H₂O can be formed
Explanation:
Based on the chemical reaction, 2 moles of H₂ react per mole of O₂. To anser this question we must find limiting reactant converting the mass and volume of each reactant to moles:
Moles H₂ -Molar mass: 2.016g/mol-:
8.76g * (1mol / 2.016g) = 4.345 moles
Moles O₂:
PV = nRT
PV/RT = n
P = 1atm at STP
V = 10.5L
R = 0.082atmL/molK
T = 273.15K at STP
n = 1atm*10.5L / 0.082atmL/molK*273.15K
n = 0.469 moles of oxygen
For a complete reaction of 4.345 moles moles of hydrogen are required:
4.345 moles H2 * (1mol O2 / 2mol H2) = 2.173 moles of O2 are required. As there are just 0.469 moles, Oxygen is limiting reactant
Now, 1 mole of O2 produce 2 moles of H2O. 0.469 moles will produce:
0.469 moles O₂ * (2 moles H₂O / 1mol O₂) = 0.938 moles H₂O.
The mass is -Molar mas H₂O = 18.01g/mol-:
0.938 moles * (18.01g/mol) =
16.9g of H₂O can be formedThe pressure of a sample of dry air is held constant 2.25 atm while the temperature is
decreased from 100°C to 7.0°C. The original volume of the sample is 43 L. Which of
the following is closest to the final volume of the sample?
A) 3.0L
B) 32L
C) 57 L
D) 610 L
The pressure of a sample of dry air is held constant 2.25 atm while the temperature is decreased from 100°C to 7.0°C. The original volume of the sample is 43 L. 32 L is the closest to the final volume of the sample?
What is Charles's law?A law states that the volume of an ideal gas at constant pressure is directly proportional to the absolute temperature.
Charles’ law:
[tex]\frac{V_1}{T_1}[/tex] = [tex]\frac{V_2}{T_2}[/tex]
The volume and temperature of a fixed amount of gas at a constant pressure are directly proportional.
To use the equation, the temperature must be in Kelvin.
[tex]V_2[/tex] = [tex]\frac{V_1}{T_1} XT_2[/tex]
[tex]V_2[/tex] = 32 L
[tex]V_2[/tex]= 32 L
Hence, the correct answer is B.
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The reaction for the decomposition of ammonia (NH 3 ) can be written as shownIf a student starts with 95.7 g of NH 3 , how many grams of hydrogen (H 2 ) will be produced by the reaction?
Answer:
17.0 g
Explanation:
Step 1: Write the reaction for the decomposition of ammonia
2 NH₃(g) ⇒ N₂(g) + 3 H₂(g)
Step 2: Calculate the moles corresponding to 95.7 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
95.7 g × 1 mol/17.03 g = 5.62 mol
Step 3: Calculate the moles of H₂ produced from 5.62 moles of NH₃
The molar ratio of NH₃ to H₂ is 2:3. The moles of H₂ produced are 3/2 × 5.62 mol = 8.43 mol.
Step 4: Calculate the mass corresponding to 8.43 moles of H₂
The molar mass of H₂ is 2.02 g/mol.
8.43 mol × 2.02 g/mol = 17.0 g
3. Jordan built a model of a neutral helium atom.
Nucleus
Proton
Neutron
Electron
What change would fix the mistake in Jordan's model?
Tin(II) fluoride is added to some dental products to help
prevent cavities. Tin(II) fluoride is prepared according
to the following equation:
Sn(s) + 2HF(aq) → SnF2(aq) + H2(g)
How many grams of tin(II) fluoride can be produced
from 55.0 g of hydrogen fluoride if there is plenty of tin
available to react?
Step 1: Calculate the molar mass of HF and SnF₂.
For HF
molar mass = (1.008 g/mol × 1) + (19.00 g/mol × 1)
molar mass = 20.008 g/mol
For SnF₂
molar mass = (118.7 g/mol × 1) + (19.00 g/mol × 2)
molar mass = 156.7 g/mol
Step 2: Determine the mole ratio needed.
mole ratio = 2 mol HF : 1 mol SnF₂
Step 3: Calculate the mass of SnF₂ produced by using the mole ratio.
[tex]\text{mass of SnF₂ = 55.0 g HF} × \frac{\text{1 mol HF}}{\text{20.008 g HF}} × \frac{\text{1 mol SnF₂}}{\text{2 mol HF}} × \frac{\text{156.7 g SnF₂}}{\text{1 mol SnF₂}}[/tex]
[tex]\boxed{\text{mass of SnF₂ = 215.4 g}}[/tex]
Given the balanced equation representing a reaction
occurring at 101.3kPa and 298K:
2H2 + O2 + 2H2O + 571.6kJ
What is the total amount of energy released when
0.75mol of H2O is produces?
1) 214.4 kJ
3) 285.8 kJ
2) 428.7 kJ
4) 571.6 kJ
whatisthechemicalequationforthereactionofaqueoussodiumhydroxidewithaqueoushydrochloricacid
Answer:
error disconnected
Explanation:
Oxidation elements of the numbers H2CO2
Determine the molecular formula for a compound with
an empirical formula of C2h8N and a molar mass of 46
grams per mole?
Answer:
C2H8N
Explanation:
Hello there!
In this case, since the molecular formula is the complete representation of the considered chemical compound and the empirical one is the smallest possible whole-numbered representation of the former, we infer that the ratio of the molar masses of these two provides the times in which the empirical formula is within the molecular one; for that reason, we first compute the molar mass of the empirical formula:
[tex]MM_{empirical}=12*2+8+14=46g/mol[/tex]
Thus, since the ratio is 46/46=1, we infer that the molecular formula is also C2H8N.
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Chemistry II Help please! Last question on my homework and I'm stuck.
Thank you!
Answer: [tex]\Delta G[/tex] for the reaction is -90kJ
Explanation:
The balanced chemical reaction is,
[tex]2H_2S(g)+SO_2(g)\rightarrow 3S_{rhombic}(s)+2H_2O(g)[/tex]
The expression for Gibbs free energy change is,
[tex]\Delta G=[n\times G_{products}]-[n\times G_{reactants}][/tex]
Putting the values we get :
[tex]\Delta G=[3\times G_f{S,rhombic}+2\times G_f{H_2O}]-[2\times G_f{H_2S}+1\times G_f{SO_2}][/tex]
[tex]\Delta G=[(3\times 0kJ/mol)+(2\times -229kJ/mol)]-[(2\times -34kJ/mol) +(1\times -300kJ/mol)][/tex]
[tex]\Delta G=-90kJ[/tex]
Thus [tex]\Delta G[/tex] for the reaction[tex]2H_2S(g)+SO_2(g)\rightarrow 3S_{rhombic}(s)+2H_2O(g)[/tex] is -90kJ
What is the purpose of replication?
1-to make an RNA template from DNA
2-to produce copies of a DNA molecule
3-to move mRNA through the ribosome
4-to change the number, type, or order of bases in DNA
Answer:
2-to produce copies of a DNA molecule
If a,b,c are in AP & x, y, z are in GP, prove that: x^(b-c).y^(c-a).z^(a- b) = 1
I will report if wrong.
Answer:
b
Explanation:
Match the lettered empty blanks in the following statements to the correct word that makes each statement true. When a compound dissolves in water to produce an aqueous solution, the compound is said to be Blank A in water. If an aqueous solution conducts electricity, then the solute is called a(n) Blank B. Group of answer choices Blank A [ Choose ] Blank B electrolyte
Answer:
1. Soluble.
2. Electrolyte.
Explanation:
Solubility is a term used to describe how readily a substance can be dissolved in a solvent to form a solution. Thus, a substance is said to be soluble if it dissolves completely in a solvent and insoluble if it doesn't dissolve or only dissolves partially.
For example, sodium chloride (NaCl) when mixed with water dissociates into sodium and chloride ions. Thus, salt (sodium chloride) is said to be soluble because it dissolves completely in water.
In Chemistry, dissolution can be defined as the process of dissolving or dissociating a solute in solid, liquid or gaseous phase into fragmented particles by a solvent in order to form a solution. For dissolution to occur in solids, the crystalline structure of the substance must be broken up so as to release ions, atoms or molecules to produce a solution. For liquid and gases, the substance to be dissolved must form a non-covalent bond with the solvent to produce a solution.
Hence, a compound that dissolves in water to produce an aqueous solution is said to be soluble in water. Also, the solute of an aqueous solution that conducts electricity is called an electrolyte.