Given :
Concentration of NaCl , [tex]c=0.85 \%[/tex] .
To Find :
Th amount of solid NaCl must be weighed out on the balance to prepare a bottle full containing 3500 ml .
Solution :
Concentration of NaCl is 0.85 % .
It means , 0.85 gm of NaCl in 100 ml of water .
So , amount of solid NaCl required to prepare 3500 ml solution is :
[tex]x=\dfrac{3500\times 0.85}{100}\ gm\\\\x=29.75\ gm[/tex]
Therefore , amount of solid NaCl required is 29.75 gm .
Hence , this is the required solution .
Which of these relationships is true of an uncharged atom?
A) The atomic mass is equal to the atomic number.
B) The number of electrons is equal to the number of neutrons.
C) The number of protons is equal to the number of electrons.
D) The atomic mass is equal to the number of electrons.
Answer:
The correct option is C) The number of protons is equal to the number of electrons.
Explanation:
Atoms are made up of particles called protons, neutrons, and electrons. Protons and neutrons are in the center of the atom and form the nucleus, while electrons surround the nucleus. Electrons have a negative charge. The charge of the protons is positive and finally, the neutrons have no charge.
If the atom has no charge, this means that the total charge of the atomic nucleus, which is positive due to the presence of the protons, is equal to the negative charge of the electrons, so that it cancels out.
So, the correct option is C) The number of protons is equal to the number of electrons.
Which of the following statements is a true statement concerning a reaction that has reached a state of equilibrium?
a. A system has reached equilibrium when there are equal amounts of products and reactants present in the system.
b. A system has reached equilibrium when the rate constant for the forward reaction equals the rate constant of the reverse reaction.
c. A system has reached equilibrium when the reaction has stopped and no more products are formed.
d. A system has reached equilibrium when the concentrations of reactants and products remain constant.
Answer: A system has reached equilibrium when the concentrations of reactants and products remain constant.
Explanation:
The reactions which do not go on completion and in which the reactant forms product and the products goes back to the reactants simultaneously are known as equilibrium reactions.
The equilibrium is dynamic in nature and the reactions are continuous in nature. Rate of forward reaction is equal to the rate of backward reaction.
Equilibrium state is the state when reactants and products are present but the concentrations does not change with time, that is the concentration remains constant.
An object has a density of 16.3 g/mL and a volume of 0.46 L. Calculate the
mass of the object in pounds.
Answer:
The answer is
16.50 IbsExplanation:
To find the mass of a substance given the density and volume we use the formula
mass = Density × volumeFrom the question
Density = 16.3 g/mL
volume = 0.46 L
We must first convert the volume from L to mL
If 1 L = 1000 mL
Then 0.46 L = 0.46 × 1000 = 460 mL
Substitute the values into the above formula and solve
That's
mass = 16.3 × 460 = 7498 g
To convert the mass from g to lbs we use the conversion
1g = 0.0022 Ibs
If 1 g = 0.0022 Ibs
Then 7498 g = 7498 × 0.0022
We have the final answer as
16.50 IbsHope this helps you
A certain block is floating in water with 77% of itself submerged. It has a length of 4.3 cm, a width of 5.9 cm, and a height of
2.75 cm. What is its mass, in kilograms?
a. 1.86 kg
b. 2.77 kg
c. 0.0086 kg
d. 5.98 kg
e. 3.62 kg
f. 0.0537 kg
Answer:
f. 0.0537 kg
Explanation:
To solve this, we use the formula for force of buoyancy (Fb) = Vs × D × g
Where; Fb= Force of buoyancy
Vs= Volume of submerged
block
D= Density of water that block
submerges in
g= acceleration due to gravity
In this question, volume of block can be calculated using L×B×H
= 4.3cm × 5.9cm × 2.75cm = 69.7675cm^3
If 77% of the block is submerged in water, then 77/100 × 69.7675cm^3
= 53.72cm^3 is the Volume of submerged block
Density of water is known as 1000kg/m^3 while the gravitational force is 10m/s^2
We need to convert the Vs (volume of submerged block) to m^3 by dividing by 1,000,000
Hence, Vs = 53.72/1000000
Vs= 0.00005372m^3
Using the formula; (Fb) = Vs × D × g
Fb = 0.00005372m^3 × 1000kg/m^3 × 10m/s^2
Fb = 0.5372kg/m/s^2
Therefore, the force of buoyancy of the object on water is 0.5372kg/m/s^2
Recall that; Mass (m) = Volume (V) × Density (D)
Force of buoyancy (Fb) = Vs×D = mass (m) × acceleration due to gravity (g)
i.e. mass = Fb/g
= Mass of the block = 0.5372/10
Mass = 0.05372kg
Therefore, the mass of the block in kg is 0.05372kg
Can someone help me please I can’t get this hi
Which property of matter during a chemical change but does not change during a physical change
Answer:
The difference between physical change and chemical change is that chemical reaction is composition there is a change in the composition substances in question. In a physical change, there is a difference in the appearence, smell, or simple display of a sample matter
Explanation:
What is the mass number of an
atom which contains 21 electrons,
21 protons, and 24 neutrons?
21
66
42
45
Answer:
66 i think
Explanation:
because i add 21+21+24=66
Select the appropriate shape for the given volume formula
Answer: Cylinder , Sphere , Rectangular prism , Cone
i did an online work
How are sheep used as a symbol in the alchemist book?
Explanation:
Santiago's sheep in the novel alchemist symbolize, the sheep symbolize the ideals of modesty, simplicity and self-actualization in their peaceful yet fulfilled lives. ... Santiago also learns the lessons of life by watching his flock, and later these lessons are enhanced when he explores the desert and hears his inner voice.
PLS HELP!!
Nitric acid is made by a sequence of reactions, shown below.
4NH3(g) +5O2(g) = 4NO(g) + 6H2O(g)
2NO(g) + O2(g) = 2NO2(g)
3NO2(g) + H2O(g) = 2HNO3(g)+ NO(g)
If the first reaction occurs with 96.2% yield, the second reaction occurs with a 91.3% yield and the third reaction proceeds with a 91.4% yield,
calculate the following:
(a) The grams of nitric acid produced from 1216 grams of ammonia.
(b) The percent yield for the overall process
Answer:
from the 1st equation:
4NH3 4NO
4 *(68) 4*30
1216 X mass of NO = 536.5 g
from the 2nd Equation
2NO 2NO2
2*30 2* 46
536.5 x mass of NO2 = 822.6 grams
from the 3rd Equation
3NO2 2HNO3
3*(46) 2* (63)
822.6 X mass of nitric acid = 751.06 gram
b) % yields = ( 96.2%* 91.3% *91.4%)= 80.3%
From the list of substances, identify each as a strong acid, strong base, or neither a strong acid nor a strong baseDrag the appropriate items to their respective bins. Strong acid Strong base Neither a strong acid nor a strong baseHNO3 HCl NaCl Ca(OH)2 CH3COOH CH3NH2 CH3OH HF RbOH
Answer:
Answer is in the explanation
Explanation:
All acids that dissociates completely in water are considered strong acids. In the same way, bases that dissociates completely in water are strong bases. All hydroxides made from alkali metals and heavier alkali earth metals are strong bases.
HNO3 dissociates completely in water: STRONG ACID.
HCl dissociates completely in water. STRONG ACID.
NaCl is a salt. Neither a strong acid nor a strong base.
Ca(OH)2. Heavy alkaline earth metal. STRONG BASE.
CH3COOH an acid that doesn't dissociate completely in water. Neither a strong acid nor a strong base.
CH3NH2 is a weak base that doesn't dissociate completely in water. Neither a strong acid nor a strong base.
CH3OH. Methanol is an alcohol. Neither a strong acid nor a strong base.
HF is a weak acid; doesn't dissociate completely in water. Neither a strong acid nor a strong base.
RbOH. Is an hydroxide made from alkali metal. STRONG BASE.
What is the mass of a 67 dL sample of a salt solution?
Answer:
6733.5 g of NaCl
Explanation:
We can assume that the salt solution is a saline solution which contains NaCl in water at 0.90%, whose density is 1.005 g/ml.
So we need to apply the density concept to solve the question.
Density = mass / volume
We convert dL to mL → 67 dL . 100mL / 1 dL = 6700 mL
Density = mass / volume
Volume . Density = mass
6700 mL . 1.005 g = 6733.5 g of NaCl
Write the chemical formula for this molecule
Answer:
C2H4O
Explanation:
The chemical molecular formula is C2H4O.
Also note*: Acetaldehyde is the chemical name for this structural formula.
The atomic number can tell us how many neutrons are in an atom. Question 4 options: True False
Answer:
true i think
Explanation:
Which of the following options is correct?
All of the following are chemically modified carbohydrates except
a. galactosamine.
b. cellulose.
c. glucosamine.
d. chitin.
e. glucuronic acid.
Answer:
b. cellulose.
Explanation:
Cellulose is a polysaccharide consisting of a long chain of repeating glucose units (i.e., β-D-glucose units) that produce long unbranched chains. Cellulose can be considered as a natural polymer (i.e., a non-modified carbohydrate) because it is composed of repeated chains of β-D-glucose molecules stuck together. The cellulose polysaccharide is a principal component of plant cell walls.
Scientists are studying different jackets made for extremely cold, snowy weather. They are trying to find jackets that
are warm but also thin enough to allow for natural bodily movement.
Which question could the scientists answer scientifically?
do
O Which jacket's color looks the best?
O Which jacket traps the most heat?
O Would warm and thin jackets cost less?
Which jacket seems the most professional?
Please anybody can ya help me I have this on my test and if I fail I don’t pass this class
Draw the Lewis structure for COCl2, including lone pairs.What is the molecular shape of COCl2? The C - Cl bond in COCl2 is polar or nonpolar? What is the Cl - C - Cl bond angle? The molecule COCl2 is polar or nonpolar?
Answer:
See explanation
Explanation:
COCl2 Contains two polar C- Cl bonds due to the electro negativity difference between carbon and chlorine.
There are 24 valence electrons in COCl2, the ideal bond angle is 120° based on the valence shell electron pair repulsion theory since the molecule trigonal planar. However, the double bond present compresses the bond angle to about 111°.
The dipoles in COCl2 do not cancel out hence the molecule is polar
The Lewis structure for COCl₂, including lone pairs is attached to the image below.
Carbon (C) has 4 valence electrons, oxygen (O) has 6 valence electrons, and chlorine (Cl) has 7 valence electrons.
In this structure, the oxygen atom is double-bonded to the carbon atom, and there is a single bond between the carbon atom and each chlorine atom. The oxygen atom has 2 lone pairs of electrons.
The molecular shape of COCl₂ is linear. The carbon atom is bonded to two chlorine atoms, and there are no lone pairs on the carbon atom. Therefore, the electron domain geometry is linear.
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Element A has 15 protons. Determine the number of neutrons in its isotope with mass number 33
Answer:
18 i think
Explanation:
which has the greatest percentage of oxygen? CO2, NO2,SO2 and MgO?
Answer:
CO₂
Explanation:
Please see attached picture for full solution.
* The masses of each atom can be found in the periodic table of elements
What rules can you use to tell how many protons, neutrons and electrons make up an atom or ion?
Answer:
Explanation:
This question appears incomplete, however
The number of protons of an element/atom (atomic number) can be determined by checking for the position of the element on the periodic table. This is because elements are arranged according to there atomic number on the periodic table.
The number of electrons of any element (of a neutral atom) is equal to the number of protons of the same element.
The number of neutrons of an element/atom is determined by subtracting the atomic number of the element from it's mass number. Hence, mass number is the addition of the atomic number and the number of neutrons.
Ions are charged particles that have the same number of protons and neutrons as there parent atoms. Hence, they have different number of electrons when compared to there specific parent/neutral atom.
A negatively charged atom has more electrons than it's original atom. For example, fluoride ion (F⁻) has 10 electrons while fluorine atom has 9 electrons (meaning fluoride ion has one more electron than it's parent fluorine). The increase is dependent on the number "attached" to the charge. A positively charged atom has less electrons than it's original atom. For example, calcium ion (Ca²⁺) has 18 electrons while calcium atom has 20 electrons (meaning the calcium ion has 2 electrons less than it's parent calcium atom). As said earlier, the decrease here is also dependent on the number "attached" to the charge.
The rule used for the determination of the protons, electrons, and neutrons has been the equal number of protons and electrons, while the number of the neutrons has been the difference in the atomic mass and the protons.
The atom has been the smallest particle that has comprised of electrons, protons, and neutrons as the subatomic particle. The neutrons and protons in the atoms have consisted within the nucleus. The electrons in the atom are revolving around the nucleus.
The atoms have been consisted of an equal number of protons and electrons, while the number of neutrons has been the difference in the atomic mass and the protons.
The ions have been formed with the loss or gain of the electrons by the atom in the terms of valence electrons to complete its octet.
For more information about the electrons and protons, refer to the link:
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An ibuprofen suspension for infants contains 100 mg/5.0 mL suspension. The recommended dose is 10 mg/kg body weight. How many mL of this suspension should be given to an infant weighing 18 lb?
Answer:
32,8mL
Explanation:
1lb=2.2kg
18lb= 8.2 kg
100mg/5mL=20mg/1mL
164mg=32.8mL
plants are unable to move to a new location in response to changes in their environment. Which organelle plays a role in maintaining homeostasis in a plant?
Answer:
Plants are unable to move to a new location in response to changes in their environment. Which of the following organelles plays a role in maintaining homeostasis in a plant? a. Cell Wall b. Chloroplast c. Vacuole d. Nucleus ____ 6. In the diagram below, Cell I and II represent typical cells. In both cells,
Explanation:
:P
Answer:
Vacuole
Explanation:
did it!
Fatty acids and glycerol are the subunits of the energy storage molecules called
Answer:
true fats; triglycerides
Explanation:
Convert 75 mL of water to gallons (show work)
Answer:
[tex]\huge\boxed{\sf 75\ mL = 0.02\ gallons}[/tex]
Explanation:
1 mL = 0.000264 gallons
Multiplying both sides by 75
75 mL = 0.000264 * 75 gallons
75 mL = 0.02 gallonsA piece of metal with a mass of 611 g is placed into a graduated cylinder that contains 25.1 mL of water rising the water level 256.7 mL what is the density of the metal?
Answer:
The answer is
2.64 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 611 g
volume = final volume of water - initial volume of water
volume = 256.7 - 25.1 = 231.6 mL
The density of the metal is
[tex]density = \frac{611}{231.6} \\ = 2.638169257...[/tex]
We have the final answer as
2.64 g/mLHope this helps you
What is the purpose of a salt bridge in an electrochemical cell?
Answer:
A salt bridge, in electrochemistry, is a laboratory device used to connect the oxidation and reduction half-cells of a galvanic cell (voltaic cell), a type of electrochemical cell. It maintains electrical neutrality within the internal circuit, preventing the cell from rapidly running its reaction to equilibrium.
what was the physical property used by mendleev in creating his periodic table.
Answer:
melting point and boiling point
Explain why each molecule has a higher vapor pressure at a given temperature than the other in the pair. Match the words in the left column to the appropriate blanks in the sentences on the right. a. does not exhibit dispersion forces b. does not exhibit dipole-dipole forcescc. is polar d. has a smaller molar mass e. does not exhibit hydrogen bonding . 1. The main reasons why CH4 has a higher vapor pressure at a given temperature when compared to CH3Cl is that CH4____and_____. 2. The main reasons why H2CO has a higher vapor pressure at a given temperature when compared to CH3OH is that H2CO_____and_____.3. The main reason why CH3OH has a higher vapor pressure at a given temperature when compared to CH3CH2CH2OH is that CH3OH_____.
Complete Question
The complete question is shown on the first image
Answer:
1 The main reasons why CH4 has a higher vapor pressure at a given temperature when compared to CH3Cl is that CH4 has a smaller molar mass and does not exhibit dipole to dipole force .
2. The main reasons why H2CO has a higher vapor pressure at a given temperature when compared to CH3OH is that H2CO has a smaller molar mass and does not exhibit hydrogen bonding
3. The main reason why CH3OH has a higher vapor pressure at a given temperature when compared to CH3CH2CH2OH is that CH3OH has a smaller molar mass
Explanation:
The higher vapor pressure of the molecules at the given temperature has been based on the molar mass and the binding between the atoms of molecules.
1. The main reasons why [tex]\rm CH_4[/tex] has a higher vapor pressure at a given temperature when compared to [tex]\rm CH_3Cl[/tex] is that [tex]\rm CH_4[/tex]:
Has a smaller molar mass, and Does not exhibit dipole-dipole forcesThus options b and c are correct.
2. The main reason why [tex]\rm H_2CO[/tex] has a higher vapor pressure at a given temperature when compared to [tex]\rm CH_3OH[/tex] is that [tex]\rm H_2CO[/tex]:
Has a smaller molar mass, and Does not exhibit hydrogen bondingThus options c and e are correct.
3. The main reason why [tex]\rm CH_3OH[/tex] has a higher vapor pressure at a given temperature when compared to [tex]\rm CH_3CH_2CH_2OH[/tex] is that [tex]\rm CH_3OH[/tex]:
Has a smaller molar mass.Thus Option c is correct.
For more information about the Vapor pressure, refer to the link:
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How many atoms are in 6.30 moles of selenium (Se)?
x 10
atoms
Answer:
3.79 e+24
Explanation:
1 mol = 6.022*10^24 atoms
6.30 * ×[tex]\frac{6.022*10^2^3atoms}{1mol}[/tex] = 3.79386*10^24
The answer must have 3 sig figs
A student mixed together 8 g of sugar, 5.20 g of salt
and 100.01 g of flour to make cookies. What is the TOTAL
mass (add them all together) of the mixture expressed with
the correct number of significant figures?
A) 100g
B) 113g
C) 113.21g
D) 113.2g
its C) 113.21g
u just add all the masses