Answer:
47.8 %
Explanation:
Ar of Zn = 65
Mr of ZnCl2 = 65 + (2 * 35.5)
= 65+ 71
= 136
Percentage Composition
= ( Ar of element × No of atom in formula ) / Mr of compound * 100 %
% composition of Zn = ( 65*1 )/ 136 × 100 %
= 47.7941...
= 47.8 % ( 3 s.f )
which safety symbol would you expect to see on a can of insect repellant?
Answer:
Pesticides. They are labelled to help identify their toxicity.
In the sketch area, draw a dot diagram for the below compound. Make sure to show the transfer of electrons and the resulting positive and negative ions Na2S
Answer: For ionic compounds, the ratio in which. positive & negative ions combine is ratio that achieves charge neutrality for resulting compound.
Explanation:
Identify the following reactions as combination, decomposition, or combustion reactions
C7H8 + 9O2 → 7CO2 + 4H2O ______________
2NaHCO3 → Na2CO3 + H2O + CO2 ___________
CH4 → C + 2H2O ________________
P4O10 + 6H2O → 4H3PO4 ______________
FeSO4 → FeO + SO3 _______________
CaCO3(s) → CO2(g) + CaO(s) _________________
Answer:
1. combustion
2. decomposition
3. decomposition
4. combination
5. decomposition
6. decomposition
Explanation:
combination of a reaction is when 2 more or elements/ compounds combine to form a compound. example: (A+B→AB)
decomposition of a reaction is when a chemical breakdown. example: (AB→A+B)
a combustion reaction is when an element/ compound reacts with oxygen to form the product of water and carbon dioxide.
example: ( [tex]C_{x}[/tex] [tex]H_{y}[/tex] + [tex]O_{2}[/tex] → [tex]H_{2}[/tex]O + [tex]CO_{2}[/tex] )
Calculate the number of moles of KOH in 6.70 mL of a 0.480 M KOH solution. (Enter your answer in scientific notation.)
Answer:
3.2×10^-3 mol
Explanation:
The equation for molarity is M= n/L. Where "M" is Molarity, "n" is the number of moles of solute, and "L" is the total liters in solution.
The question gives you the volume in mL, so to convert "mL" to "L" you need to divide by 1000. (6.70mL/ 1000L)= 0.0067L.
Now you can plug the numbers into the equation. 0.480M= n/ 0.0067L), multiply (0.480M×0.0067L)= 0.003216 mol. The scientific notation is 3.2×10^-3, 10^-3 because you move the decimal back three times and 3.2 because there are 2 sig figs.
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The rate of the given reaction is 0.840 M/s.
A +4B - 2C
What is the relative rate of change of each species in the reaction?
This problem is providing the rate of the given reaction as 0.840 M/s and asks for the relative rate of change of each species. At the end, the results turned out to be -0.840 M/s, 0.210 M/s and 0.420 M/s for A, B and C respectively.
Relative rate of changeIn chemical kinetics, when chemical reactions take place, it turns out possible for us to quantify in what extent a reaction is proceeding over time, by overseeing the change in the concentration as the time goes by.
In such a way, when given the rate of reaction, one can calculate the relative rate of change of each species by using the following equation, involving their stoichiometric coefficients in the reaction:
[tex]r_A=\frac{r}{-1} \\\\r_B=\frac{r}{-4} \\\\r_C=\frac{r}{2}[/tex]
Where these coefficients are negative for reactants and positive for products. In such a way, one can plug in the given rate of reaction to obtain each species' as follows:
[tex]r_A=\frac{0.840M/s}{-1} =-0.840M/s\\\\r_B=\frac{0.840M/s}{-4} =0.210M/s\\\\r_C=\frac{0.840M/s}{2}=0.420M/s[/tex]
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hi everyone, I am getting stuck in this question can you tell me it please ,what are the property's of a metal and a non-metal
Answer:
Explanation:
Properties of Metal
1. Metals are ductile. ...
2. Metals are a good conductor of heat and electricity.
3. Metals have high tensile strength. .
4. Metals are sonorous.
5. Metals are hard.
Properties of non metal
1. High ionization energies.
2. High electronegativities.
3. Poor thermal conductors.
4. Poor electrical conductors.
5. Brittle solids—not malleable or ductile.
6. Little or no metallic luster.
7. Gain electrons easily.
the inner part of the ovary that contains an egg is the ovule
true or false
Answer:
The answer is true
Explanation:
the ovary is a tubular structure and contains ovules
The model here shows a process by which a hydra, an aquatic organism, produces a new offspring that is a clone of the original organism. If a student is explaining how the organism creates its own clone, which process would be included in the explanation? A) mitosis B) meiosis C) fertilization D) binary fission
The reproduction of hydra is through budding process from its body. This process of regeneration is called mitosis.Mitosis is a type of cell division process. Thus option A is correct.
What is mitosis?Mitosis is a cell division process in which one cell produces two identical daughter cells. The term mitosis means the duplication of the genetic material chromosomes with the exact gene information.
Different stages in mitosis together is called mitotic phases. Hydra is an invertebrate freshwater organism. Hydra has a translucent tubular body which can be elongated and contracted.
Hydra is classified to the phylum hydrozoa. It have a regeneratable head. The reproduction of hydra is through budding. A small bud first projects from its tubular body which then develops and emerges out by cell division.
The divided daughter hydra will grow as a matured hydra. This overall budding process takes places through mitosis. Hence, option A is correct.
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I wonder what avocado is made of
Answer:
The avocado consists of around 73% water, 15% fat, 8.5% carbohydrates — mostly fibers — and 2% protein. Half an avocado, at around 100 grams (g) contains 160 calories ( 1 ).
CaCO2=CaO + CO₂
How do I balance this equation?
Does the food you eat can affect your gut bacteria? Explain?
Answer: Your gut bacteria can affect how your food is digested, how fat is stored and whether you feel hungry or full.
Explanation: Thus, a healthy gut bacteria may be important for maintaining a healthy weight. High-fiber foods like whole grains, fruits, vegetables, nuts and seeds can all promote healthy gut bacteria.
1. Consider the following reaction where Kc = 1.29×10-2 at 600 K.
COCl2(g) CO(g) + Cl2(g)
A reaction mixture was found to contain 9.87×10-2 moles of COCl2(g), 2.19×10-2 moles of CO(g), and 3.79×10-2 moles of Cl2(g), in a 1.00 liter container.
Is the reaction at equilibrium?
If not, what direction must it run in order to reach equilibrium?
The reaction quotient, Qc, equals _____
The reaction:
A. must run in the forward direction to reach equilibrium.
B. must run in the reverse direction to reach equilibrium.
C. is at equilibrium.
2. Consider the following reaction where Kc = 55.6 at 698 K.
H2(g) + I2(g) 2HI(g)
A reaction mixture was found to contain 2.59×10-2 moles of H2(g), 4.38×10-2 moles of I2(g) and 0.294 moles of HI(g), in a 1.00 liter container.
Is the reaction at equilibrium?
If not, what direction must it run in order to reach equilibrium?
The reaction quotient, Qc, equals ____
The reaction:
A. must run in the forward direction to reach equilibrium.
B. must run in the reverse direction to reach equilibrium.
C. is at equilibrium.
Answer:
Consider the following reaction where Kc = 1.29×10-2 at 600 K:
COCl2(g) <=> CO(g) + Cl2(g)
A reaction mixture was found to contain 9.85×10-2 moles of COCl2(g), 2.61×10-2moles of CO(g), and 3.71×10-2 moles of Cl2(g), in a 1.00 Liter container.
Indicated true (T) or false (F) for each of the following:
How do I Determine the number of moles in 3.51 x 1023 formula units of CaCl2.
Answer:
I used a picture
Explanation:
Hope it helps<3
A balloon containing 0.040 mol of a gas with a volume of 5.0 mL was expanded to 1.0 L.
Which equation should you use to find the amount of gas added?
Answer:
B) n2=V2N1/V1
the second part is 0.080
Explanation:
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The volume and number of moles of a gas are in direct proportion. Hence, as the volume increases from 5 ml to 1 L, number of moles increases from 0.040 to 8 moles.
What is Avogadro's law?Avogadro's law, states that, at constant pressure and temperature, the number of moles of a gas is directly proportional to the volume of the gas. Hence,
V1/n1 = V2/n2, for two different volumes.
Given that, v1 = 5 ml
v2 = 1 L = 1000 ml
n1 = 0.040 mol
then n2 = v2 n1/ v2
Number of moles at 1 L = (0.040 mol × 1000 ml)/5 ml = 8 moles.
Hence, the number of moles of the gas added = 8 - 0.040 = 7.96 moles.
Therefore, the amount of gas added at the increased volume is 7.96 moles.
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If you evaporated 125 mL of a 3.5 M solution of iron(II) nitrite, how many moles of iron(II) nitrite would you recover?
Considering the definition of molarity, 0.4375 moles of iron(II) nitrite you would recover.
In order to find the moles of the solid that can be recovered from this solution, you need to use the definition of molarity.
Definition of molarityMolar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liters}[/tex].
Moles of iron(II) nitrite
In this case, you evaporated 125 mL of a 3.5 M solution of iron(II) nitrite. Then you know:
Molarity= 3.5 Mnumber of moles= ?volume= 125 mL= 0.125 L (being 1000 mL= 1 L)Replacing in the definition of molarity:
[tex]3.5 M=\frac{number of moles}{0.125 L}[/tex]
Solving:
number of moles= 3.5 M× 0.125 L
number of moles= 0.4375 moles
Finally, 0.4375 moles of iron(II) nitrite you would recover.
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what kind of weather would you associate with a high pressure system? how does the density, humidity, and air motion compare to that of a low pressure system
type your answer here:
Answer:
High pressure and low pressure have two distinct types of weather associated with them...typically. High pressure often means dry weather with sunshine. Low pressure often means clouds and precipitation. High pressure is associated with sinking air.
Explanation:
High-pressure systems are usually called Fair Weather Systems because the 7 types of weather in a high-pressure zone are generally comfortable and clear. Keep in mind that high and low pressures mean the air is under higher or lower pressure relative to the surrounding air.
Which location in the image below represents the OLDEST rocks?
A and C are the only two places that would represent the oldest rocks
An engine cylinder contains 175 mL of gas at a pressure of 1.0 atm. As the engine runs, it compresses the cylinder, reducing the volume of the gas to 15 mL. What is the new pressure of the gas at this volume?
This problem is providing the initial volume and pressure of a gas in an engine cylinder and asks for the final pressure once the volume of the gas has decreased due to a compression. At the end, the result turns out to be 11.7 atm.
Boyle's lawIn chemistry, gas laws allow us to calculate pressure, volume, temperature or moles depending on a specified change and based on the concept and equation of the ideal gas, which derives the well-known gas laws; Boyle's, Charles', Gay-Lussac's and Avogadro's.
Thus, since this problem provides initial and final volume and initial pressure for us to calculate the final pressure, we understand we need to apply the Boyle's law as a directly proportional relationship between these two:
[tex]P_1V_1=P_2V_2[/tex]
Thus, we solve for the final pressure, P2, to get:
[tex]P_2=\frac{P_1V_1}{V_2}=\frac{1.0atm*175mL}{15mL}\\ \\ P_2=11.7atm[/tex]
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How many moles of hydrogen would be required to produce 5 mol of water?
Answer:From this you can see that 5 moles of hydrogen gas would react with 2.5 of the available 3 moles of oxygen gas, to form 5 moles of water.
Explanation:
1) How many moles of gas occupy 58 L at a pressure of 2.2 atmospheres and a temperature
of 313 K?
Here, we need to solve this problem using Ideal gas law ( PV=nRT).
Where –
P = Pressure in atmV = Volume in Ln = moles R = Ideal gas law constant T = Temperature in KNow, according to the question –
V = 58 L P = 2.2 atmT = 313 KR = 0.0821 atm L/ mol KCalculation –
[tex]\qquad[/tex] [tex]\pink{\twoheadrightarrow\bf PV = nRT}[/tex]
[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n = \dfrac{PV}{RT}[/tex]
[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n = \dfrac{ 2.2 \: \:\times 58 \: } {0.0821 \times 313}[/tex]
[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n = \dfrac{ 2.2 \times 58}{0.0821 \times 313} [/tex]
[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n =\dfrac{127.6}{25.7}[/tex]
[tex]\qquad[/tex] [tex]\pink{\twoheadrightarrow\bf n = 4.9656 \: moles }[/tex]
_______________________________________
Given Information ,
Volume ,V = 58 LPressure ,P = 2.2 atmTemperature ,T = 313We have to find the number of moles .
We use here " Ideal Gas Equation" which is
PV = nRTwhere
n is number of moles
R is universal gas Constant
T is temperature
P is pressure
V is volume
On substituting the value we get
➣ 2.2 × 58 = n × 0.0821 × 313
➣ 127.6 = n × 25.70
➣ 127.6/25.70 = n
➣ 4.96 = n
➣ 5 ≈ n
So, the number of moles are 5 .
Solve for the molecular/formula mass of the following compounds.
1. Silicon dioxide, SiO2
2. Sodium hydroxide, NaOH
3. Calcium carbonate, CaCO3
4. Sodium carbonate, Na2Co3
5. Silver nitrate, AgNO3
6. Iron oxide, FeO.
7. Phosphoric acid, H2PO4
8. Sodium bicarbonate, NaHCO3
9. Acetic acid, CH3COOH
10. Sodium fluoride, NaF
Answer:
what you need to do is,
you take the relative atomic mass of each element and multiply it by the no of atoms it has. do this for all the elements present, and add the values. that's it!
Explanation:
try to do the last one by yourself, it is easy and you will be using the molecular/formula mass mostly everywhere in chemistry.
is CO2 a covalent or ionic bond? will give brainliest for the correct answer
Answer:
covalent bond
Explanation:
a covalent bond happens between two nonmetals
a ionic bond happens between a metal and a non metal
CO2 is a bond between carbon and oxygen
carbon and oxygen are both non metals therefore CO2 is a covalent bond
G. A gas is at currently at STP. What volume will the
gas have at 100°C and 5.0 atm?
Answer:
[tex]less \: than \: 10 \: litres \: [/tex]
Explanation:
At 100℃,P=1atm
V=10L
At NTP, T=20
P=1atm
PV=nRT
PV=nRTV∝C
So at NTP temp is less than 100℃ and as the volume is proportional to temperature.
So at NTP temp is less than 100℃ and as the volume is proportional to temperature.Thus, the volume will be less than 10L as the temperature decreases.
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How are water particles affected by the movement of a wave?
•
The wind pushes the water particles down to deeper depths.
O The wave pushes the water particles back and forth.
•
The water particles move in an upward motion through the wave.
The water particles move in a circular pattern.
Answer:
The water particles move in an upward motion through the wave.
Explanation:
When water particles become part of a wave they start to move up or down.
Answer:
u deleted my answer before so
Explanation:
Please help! THIS IS DUE IN A HOUR!
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1. Calculate the energy of an X-ray photon if the wavelength is 5.00x10^-10m?
2. (use picture) Determine the energy related to an electron occupying the ground state a Hydrogen atom given its bright-line spectrum below (the one to the left with least frequency):
3. A laser used to detach retinas produces radiation with a frequency of 4.6x10^14 Hz. What is the wavelength of this light?
[tex]\bold{\huge{\pink{\underline{ Answer }}}}[/tex]
Concept Used :-Here, we will use the concept of planks quantum theory .
According to planks quantum theory :-
The radiant energy is emitted discontinuously in the form of small packets of energy called quantaIn case of lights, It is called photons The amount of energy with each quantum of radiation is directly proportional to the frequency of light That is, E = hv or E = hc/ λThe total amount of energy emitted or a absorbed will be whole number multiple of quantum That is, E = nhv or nhc/λAnswer 1 :-Here,
We have to calculate the energy of an X photon
The wavelength is 5.00 × 10^-10The value of planks constant h is 6.626 × 10^-34 .According to the planks quantum theory of radiation :-
[tex]\bold{\pink{ E = hv }}[/tex]
[tex]\sf{ E = h}{\sf{\times{\dfrac{c}{λ}}}}[/tex]
The value of c is 3 × 10^8Subsitute the required values,
[tex]\sf{ E = 6.626 × 10^{-34} }{\sf{\times{\dfrac{3 × 10^{8}}{5 × 10^{-10}}}}}[/tex]
[tex]\sf{ E = }{\sf{\dfrac{19.87× 10^{-26}}{5 × 10^{-10}}}}[/tex]
[tex]\sf{ E = 3.974 × 10^{-36}}[/tex]
Hence, The energy of an X ray photon is 3.974 × 10^-36
Answer 2 :-We have ,
Frequency = 4.57 × 10^14 HzPlanks constant = 6.626 × 10^-34According to the planks quantum theory,
[tex]\bold{\pink{ E = hv }}[/tex]
Subsitute the required values,
[tex]\sf{ E = 6.626 × 10^{-34}× 4.57 × 10^{14}}[/tex]
[tex]\sf{ E = 30.28 × 10^{- 20}}[/tex]
[tex]\sf{ E = 3.028 × 10^{ - 19}}[/tex]
Hence, The energy related to an electron occupying the ground state of hydrogen atoms is 3.028 × 10^-19
Answer 3 :-We have ,
Frequency = 4.6 × 10^14 HzWe know that,
[tex]\bold{\pink{ v = }}{\bold{\pink{\dfrac{ c }{λ}}}}[/tex]
[tex]\sf{ λ = }{\sf{\dfrac{ c }{v}}}[/tex]
Subsitute the required values,
[tex]\sf{ λ = }{\sf{\dfrac{ 3 × 10^{8} }{4.6 × 10^{-14}}}}[/tex]
[tex]\sf{ λ = 0.65 × 10^{22}}[/tex]
Hence, The of this light is 0.65 × 10^22 .
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According to the following reaction, how many grams of oxygen gas are required for the complete reaction of 21.2 grams of hydrogen sulfide?
hydrogen sulfide (g) + oxygen (g) water (l) + sulfur dioxide (g)
_____grams oxygen gas
Answer:
29.9g please refer to the picture for work
true or false: chemical reactions are usually written left to right
How many moles (of molecules or formula units)
are in each sample?
75.83 g CF2Cl2
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Davy made a model of the water cycle by adding some water inside a plastic bag, sealing the bag, and placing it in a sunny area. He noticed that the level of the water went down, and then some droplets appeared on the sides of the bag. Which part of the water cycle caused water droplets to form on the side of the plastic bag?
Condensation
Evaporation
Precipitation
Runoff
Answer:
precipitation
Explanation: