Answer:
4
Explanation:
Four significant figures
Protons have about the same mass as
Answer:
[tex]\Large \boxed{\mathrm{neutrons}}[/tex]
Explanation:
Protons have about the same mass as neutrons.
Protons have a mass of 1 amu
Neutrons have a mass of 1 amu
Electrons have a mass of 1/1836 amu
Answer:
Protons and neutrons have approximately the same mass,
Explanation:
1.6726219 × 10^-27 kilograms is the mass of protons as well as neutrons
Phosphorus trichloride, PCl3, is commonly used in the chemical industry as a source of phosphorus in various reactions. Indicate the electron pair geometry and the molecular geometry of the PCl3 molecule.
Answer:
Electron pair geometry- tetrahedral
Molecular geometry- Trigonal Pyramidal
Explanation:
PCl3 has four electron domains on the outermost shell of the central atom in the molecule. This implies that it has a tetrahedral electron pair geometry according to Valence Shell Electron Pair Repulsion theory.
These four electron pairs are composed of three bond pairs and one lone pair. The presence of a lone pair of electrons leads to a trigonal pyramidal molecular geometry due to electron pair repulsions.
Which reactant in each of the following pairs is more nucleophilic? Explain.a. -NH2 or NH3b. H20 or CH3CO2-c. BF3 or F-d. (CH3)3P or (CH3)3Ne. I- or Cl-f. -C triple bonded to N or -OCH3
Answer:
I^- or Cl^-
Explanation:
A nucleophile is any reagent that donates an unshared pair of electrons to form a new covalent bond. Nucleophiles are mostly bases also. Nucleophilicity is a kinetic property, it refers to the rate at which a nucleophile replaces a leaving group from an alkyl halide.
Looking at the options, Cl^- and I^- are the best nucleophiles among the options provided in the question.
What is the cost of 4 oranges, if 6 oranges weigh 2.4 pounds and the price of oranges are
$0.50 per pound?
Answer:
$.80
Explanation:
2.4 / 6 = 0.4
0.4 lbs per orange
0.4 x 4 = 1.6
4 oranges = 1.6 lbs
1.6 x 0.50 = $0.80
Cost is the price or the amount required to purchase a product by money. The four oranges will cost $0.80 if six oranges weigh 2.4 pounds and $0.50 per pound.
What is the cost?The cost has been used in commerce and accounts and is defined as the monetary amount required by the person to pay for purchasing the object. The amount of the object can be based on various proportions. The cost of bananas can be estimated by the unitary method.
Given,
Weight of six oranges = 2.4 pounds
Price of oranges per pound = $0.50
At first, the weight of one orange is calculated as:
If 6 oranges = 2.4 pounds
Then, 1 orange = 0.4 pounds per orange
Second, the weight of four oranges is calculated as:
1 orange = 0.4 pounds
4 oranges = 1.6 pounds
Third, the cost of four oranges is calculated as:
1 pound = $0.50
1.6 pounds = $0.80
Therefore, 4 oranges cost $0.80.
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A sample of 2.00 mol of gas in a 10.00 L container is at 45.0 °C. What is the pressure (in atm) of the gas?
Answer:
5.22 atm
Explanation:
The following data were obtained from the question:
Number of mole (n) = 2 moles
Volume (V) = 10 L
Temperature (T) = 45 °C
Pressure (P) =?
Next, we shall convert 45 °C to Kelvin temperature. This can be obtained as follow:
Temperature (K) = Temperature (°C) + 273
T (K) = T (°C) + 273
T (°C) = 45 °C
T(K) = 45 °C + 273
T (K) = 318 K
Finally, we shall determine the pressure of the gas by using the ideal gas equation as shown below:
Number of mole (n) = 2 moles
Volume (V) = 10 L
Temperature (T) = 318 K
Gas constant (R) = 0.0821 atm.L/Kmol
Pressure (P) =.?
PV = nRT
P x 10 = 2 x 0.0821 x 318
Divide both side by 10
P = (2 x 0.0821 x 318) /10
P = 5.22 atm
Therefore, the pressure of the gas is 5.22 atm
How many dm³ of hydrogen,measured at s.t.p.,would be needed to reduce 47.7g of copper(II) oxide to copper?
A. 4.48
B. 6.72
C. 10.82
D. 13.44
Answer:
Option D. 13.44
Explanation:
We'll begin by calculating the number of mole in 47.7g of copper(II) oxide, CuO.
This can be obtained as follow:
Mass of CuO = 47.7 g
Molar mass of CuO = 63.5 + 16 = 79.5 g/mol
Mole of CuO =.?
Mole = mass /Molar mass
Mole of CuO = 47.7/79.5
Mole of CuO = 0.6 mole
Next, we shall write the balanced equation for the reaction. This is given below:
CuO + H2 —> Cu + H2O
From the balanced equation above,
1 mole of CuO reacted with 1 mole of H2 to produce 1 mole of Cu and 1 mole of H2O.
Next, we shall determine the number of mole of H2 needed to react completely with 0.6 mole of CuO.
This can be obtained as follow:
From the balanced equation above,
1 mole of CuO reacted with 1 mole of H2.
Therefore, 0.6 mole of CuO will also react with 0.6 mole of H2.
Finally, we shall determine the volume occupied by 0.6 mole of H2 at STP.
This can be obtained as follow:
1 mole of H2 occupied 22.4 dm³ at STP.
Therefore, 0.6 mole of H2 will occupy = 0.6 × 22.4 = 13.44 dm³.
Therefore, 13.44 dm³ of H2 is needed for the reaction.
A(n) _______________ can be formed by linking together several monosaccharides via glycosidic bonds.
Answer:
A polysaccharide (n) can be formed by linking several monosaccharides through glycosidic linkages.
Explanation:
Polysaccharides are carbohydrates or complex carbohydrates, where monosaccharides join with glucosidic bonds to form a more complex structure that would be the polysaccharide.
An example of a polysaccharide is starch, or glycogen.
Starch is found in many foods such as potatoes or rice, and glycogen is a form of energy reserve of our organism housed in muscles and liver to fulfill locomotion, physical activity, and other activities that consist of glycolysis.
Polysaccharides are degraded in our body by different stages, and several enzymes unlike monosoccharides or disaccharides, since they have more unions and a more complex structure to disarm in our body and thus assimilate it.
Polysaccharides are also part of animal structures, such as insect shells or nutritional sources, among others.
who can help me think of a good observation then a hypothesis thanks!
g What is the major problem with using Friedel-Crafts alkylation to mono-alkylate an aromatic ring?
Answer:
Explanation:
Following are the problems to mono-alkylate the aromatic ring .
1 ) The carbocations formed in the process undergo rearrangement when the number of carbon to be added in the alkylation process is more than two .
2 ) The formed monoalkylated product is more reactive than reactant so reaction does not stop after monoalkylation . Dialkylation and tri alkylation product too are simultaneously formed . This can be controlled by using benzene in excess as reactant . Monohalo benzene or nitrobenzene are too weak to undergo Friedel craft reaction because of presence of deactivating
group .
What is this If 3x+2=6 what is the value of x
Answer:
[tex]\Huge \boxed{x =\frac{4}{3} }[/tex]
[tex]\rule[225]{225}{2}[/tex]
Explanation:
[tex]3x+2=6[/tex]
Subtracting 2 from both sides.
[tex]3x=4[/tex]
Dividing both sides by 3.
[tex]\displaystyle x =\frac{4}{3}[/tex]
[tex]\rule[225]{225}{2}[/tex]
The following pairs of aqueous solutions are separated by a semipermeable membrane. In which direction will the solvent flow?a. A = 3.45 M calcium iodide; B = 3.45 M sodium bromideb. A = 5.00 M sucrose; B = 3.00 M potassium nitrate
Answer:
osmosis is a process where by solvent or fluid molecules flow from low concentration to high concentration.
So in
A.solvent will flow from B to A because
B = 3.45 M sodium bromide is more concentrated than 3.45 M calcium iodide;
b) solvent still flow from B to A because
A = 5.00 M sucrose is less concentrated than B = 3.00 M potassium nitrate
at critical humidity the rate of corrosion is
Answer:
Corrosion of carbon steel occurs when the relative humidity of the air is 70% to 80% and the air temperature is above 32 F.
Hope this helps you :)
A dihalide in which the halogens are attached on adjacent carbons is called a _______________ dihalide.
Answer:
Vicinal dihalide
Explanation:
Dihalide in which the halogens are attached on adjacent carbons are called Vicinal dihalides.
They are prepared by reaction between halogen and alkyne and alkene. For example, 1,2-dichloroethane which is given by the reaction between ethylene and chlorine.
What ultimately determines what type of solution you have? Why can’t we just use this property? Explain in terms of the tyndall effect
Answer:
The solutions are classified according to their ability to scatter light rays.
We can't just use this property because some true solutions also contain undissolved solute.
Explanation:
Tyndall effect refers to the ability of a solution to scatter light rays. True solutions do not scatter light rays while false solutions scatter light rays.
Colloid particles are not large enough to be seen with naked eyes unlike suspensions. We should not confuse a colloid with a suspension because in a suspension, the dispersed solutes are seen with naked eye.
What is the normality of 500ml
Solution of Sodium hydroxide Containing 30 gm naoh?
Answer:
[tex]N=1.5N[/tex]
Explanation:
Hello,
In this case, since normality is defined in terms of the equivalent grams and the volume of the solution:
[tex]N=\frac{eq-g}{V}[/tex]
We need to compute the equivalent grams by considering that the molar mass of NaOH is 40 g/mol and one mole of NaOH contains one equivalent grams due to the presence of one hydroxyl ion only:
[tex]eq-g=30gNaOH*\frac{1molNaOH}{40gNaOH} *\frac{1eq-g}{1mol}=0.75eq-g[/tex]
And the volume in liters (0.500 L). Therefore, we obtain:
[tex]N=\frac{0.75eq-g}{0.500L} \\\\N=1.5N[/tex]
Regards.
Water found in streams, depressions,and from the ground must first bepurified since all water sources should be considered as being contaminated. Which of the followingis not an acceptable method for water purification?a. Adding 2 drops of iodine or bleach toa quart of waterb. Use a commercially produced charcoalfilterc. Boiling the water for 2 minutesd. Filtering the water through a tight-mesh cloth
Answer:
Use a commercially produced charcoalfilter
Explanation:
Water found in streams, depressions and ground water must be contaminated with pathogenic microorganisms. The methods of disinfection using iodine or bleach or boiling the water for about two minutes and then filtering it with a clean cloth will effectively remove the microorganisms.
However, charcoal filters do not eliminate microorganisms from water hence this method is not acceptable in this case.
explain atomic mass
The atomic mass or atomic weight is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that specific isotope.
You can calculate the mass of the atom by adding together the number of protons and neutrons and multiplying by 1 amu.Find the final temperature of water given an initial temperature of 28 °C, a mass of 5 kg, heat (q) of 184 J. (Specific Heat of water = 4.184). a. 19.2°C b. 36.8 °C c. 38.8 °C d. 3880 °C
Explanation:
Initial temp = 28 °C
Final Temp = ?
Heat = 184 J
mass = 5 g
c = 4.184 joule/gram °C
The relationship between these parameters is given by the equation;
H = mCΔT
ΔT = H / mC
ΔT = 184 / 5(4.184)
ΔT = 184 / 20.92
ΔT = 8.8 °C
ΔT = Final Temp - Initial Temp
Final Temp = Initial Temp + ΔT
Final Temp = 28°C + 8.8 °C
Final Temp = 36.8°C
For each of the experiments described below, design a table to record the results.
Experiment 1: Simon is investigating mass changes during chemical reactions. He investigates the change in mass when magnesium ribbon is oxidised to form magnesium oxide:
magnesium + oxygen magnesium oxide
He records the mass of an empty crucible. He places a 10 cm strip of magnesium ribbon in the crucible and records the new mass of the crucible. He heats the crucible strongly until all the magnesium ribbon has reacted to form magnesium oxide. He allows the crucible to cool before recording the mass of the crucible and magnesium oxide.
Answer:
stupidddd guhhhhhuiijui
Which of the following events fail to follow the law of conservation of matter? Select the correct answer below
A) Burning wood for a fire
B) Freezing water into ice cubes
C) The decomposition of MgCl, into Mg and Cl
D) None of these
Answer:
d
Explanation:
you just cant
The law of conservation of matter defines the preservation of the mass of the reactant and the product. All the matter in the universe is bound to follow the law. Thus, option D is correct.
What is conservation of matter?The law of conservation of matter or mass is the principle that states how the mass of the reaction system remains constant no matter what the reaction is. For any closed system, the mass can't change when undergoing changes.
When wood is burned for fire, water is frozen for ice, and magnesium chloride decomposes to produce chloride and magnesium then, the masses of the reactant and the product remain constant. There may be a chance that the mass seems to decrease in a reaction but it is due to changes in the phase of matter and no actual mass is lost.
Therefore, option D. none of these fails the law of conservation of matter.
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Which metal is used to make foils for packaging of food?
Explanation:
aluminium metal is used to make foils for packaging of food
aluminum metal is best used for packaging foods
lodine has a density of 4.94 g
/mL. What is its density in lb/gal? (1 gal= 3.785 L and 1 lb = 454 g) *
41.2 lb/gal
18.7 lb/gal
8490000 lb/gal
0.0412 lb/gal
348 lb/gal
Answer:
41.2 lb/gal
Explanation:
Step 1: Given data
Density of iodine: 4.94 g/mL
Step 2: Convert the mass to grams
We will use the conversion factor 1 lb = 454 g.
4.94 g/mL × (1 lb / 454 g) = 0.0109 lb/mL
Step 3: Convert the volume to gal
We will use the conversion factors 1 gal= 3.785 L and 1 L = 1,000 mL.
0.0109 lb/mL × (1,000 mL/1 L) × (3.785 L/1 gal) = 41.2 lb/gal
A balloon under 1 atm of pressure contains 10.0 g of neon gas. With the temperature kept constant, 15.0 g of xenon gas is added. What happens?
Answer:
The volume of the ballon expands 1.2 times
Explanation:
The pressure in the ballon will be always the same. And as temperature is also the same the only parameters that change are moles of gas and volume.
The volume is directely proportional to moles of the gas under pressure and temperature constant (Avogadro's law). That means:
V₁ / n₁ = V₂ / n₂
Where V is volume and n moles of 1, initial statet and 2, final state of the gas
Initial moles of Neon gas (20g/mol) are:
10.0* (1mol / 20g) = 0.5 moles are equal to initial moles that occupies X liters of volume.
As you add 15.0g of Xe (Molar mass: 131g/mol):
15.0g * (1mol / 131g) = 0.11 moles + 0.55 moles = 0.66 moles that are final moles.
Replacing in Avogadro's law:
V₁ / n₁ = V₂ / n₂
X L / 0.55moles = V₂ / 0.66 moles
1.2X L = V₂
That means the volume of the ballon expands 1.2 times
The liquid 2-chloro-2,3-dimethylbutane has a density of 0.878 g/mL at 20.0°C. If a 138 gram sample of this compound is needed, what volume of the liquid at 20.0°C must be provided? volume= mL
Answer:
157 mL
Explanation:
Step 1: Given data for 2-chloro-2,3-dimethylbutane
Density (ρ): 0.878 g/mL
Mass (m): 138 g
Volume (V): ?
Step 2: Calculate the volume of the liquid required
The density of a compound is equal to its mass divided by its volume. We will use the following expression.
ρ = m / V
V = m / ρ
V = 138 g / (0.878 g/mL)
V = 157 mL
Which one of the following substances would be the least soluble in CCl4?
(a) I2
(b) Na2SO4
(c) HI
(d) C2H6
(e) CH3CH2OH
Answer:
Na2SO4
Explanation:
Chemistry operates on the principle of 'like dissolved like'. This implies that polar solvents dissolve polar substances while nonpolar solvents dissolve nonpolar substances.
This is because, dissolution of a substance in a solvent is as a result of intermolecular interaction between solute and solvent.
Since Na2SO4 is purely an ionic substance and CCl4 is purely a nonpolar solvent, Na2SO4 is least soluble in CCl4.
3.5 cm in length x 3.2 in height x 0.3cm in with calculate the volume
Answer:
volume = area×breadth×height
Explanation:
answer is 3.36
Using the thermodynamic information in the ALEKS Data tab, calculate the standard reaction entropy of the following chemical reaction:
S8 + 24F2------ 8S + F6
Round your answer to zero decimal places.J/K
Answer:
[tex]\Delta _rS\°=-2965.27J/K[/tex]
Explanation:
Hello,
In this case, for the considered reaction, the standard reaction entropy is computed considering the standard entropy of each product and reactant and their stoichiometric coefficients as shown below:
[tex]\Delta _rS\°=8*S\°_{SF_6}-S\°_{S_8}-24*S\°_{F_2}[/tex]
Thus, considering the ALEKS Data tab, we obtain:
[tex]\Delta _rS\°=8*(291.52J/K)-(430.23J/K)-24*(202.8J/K)\\\\\Delta _rS\°=-2965.27J/K[/tex]
Regards.
Which of the following is an example of pseudoscience?
a. Finding a new star
b. Predicting your horoscope
C. Dating the age of a fossil
d. Finding new uses for drug
Answer:
b. Predicting your horoscope
Explanation:
Pseudoscience refers to claims that are scientifically misleading and do not follow the scientific method. For example, imagine someone claims a certain drug will make you live forever. This is an example of pseudoscience. It has not been tested using the scientific method and it is misleading.
The scientific method follows this general structure.
1. Ask a question
2. Do background research
3. Construct a hypothesis
4. Test your hypothesis
5. Analyze data and draw a conclusion
6. Communicate your results. (Was your hypothesis correct?)
Finding a new star, dating the age of a fossil, and finding new uses for a drug all are processes that use the scientific method. Predicting your horoscope is not a science and it has not been proven using the scientific method.
An example of pseudoscience is " predicting your horoscope".
What is pseudoscience?The term "pseudoscience" refers to claims that something is both true and scientific but are somehow incompatible well with the scientific process.
What is horoscope?A horoscope would be a representation of the Sun, Moon, planets, astrological aspects, and various critical angles at the time of the occurrence, such as that of the period of a person's birth, using an astrological chart as well as a diagram.
Therefore, An example of pseudoscience is " predicting your horoscope".
Hence, the correct answer will be option (b).
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what problems can chemistry solve?
Answer:
Chemistry will help us solve many future problems, including sustainable energy and food production, managing our environment, providing safe drinking water and promoting human and environmental health.
Explanation:
Answer:
It basically does nothing
Explanation:
But I guess it teaches yout o not mix things or do things that harm people or the earth
g Write an equation showing what happens when AgNO3 is added, and explain why the equilibrium shifts
Answer:
[tex]\mathbf{AgNO_3+Cl^- \to AgCl_s + NO^{3-}}[/tex]
Explanation:
The addition of AgNO3 to the system Cl⁻ react with result into the formation a precipitate of AgNO3, as such the reactant concentration decreases.
[tex]\mathbf{AgNO_3+Cl^- \to AgCl_s + NO^{3-}}[/tex]
Suppose the concentration of a given substance is present in an equilibrium system is changed without a change in any of the other conditions, then, by le chatelier's principle, the position of equilibrium will move to decrease the concentration of the added substances. In order to relieve this constraint, the equilibrium will shift to the right favouring the forward reaction.