Answer:
wavelength = 6 cm .
Explanation:
frequency given = 5 x 10⁹ .
wavelength = velocity of light / frequency
= 3 x 10⁸ / 5 x 10⁹
= .06 m
= 6 cm
Give two examples of solutions that you might find or prepare in a kitchen.
Explanation:
solid liquid
solid gas
liquid solid
What volume will be occupied by 11.7 g of Helium in a balloon at an altitude of 10.0 km if the air pressure is 0.262 atm and the temperature is -50.0 °C?
Answer: 204 L
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 0.262 atm
V = Volume of gas = ?
n = number of moles = [tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{11.7g}{4g/mol}=2.92[/tex]
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]-50^0C=(273+(-50))K=223K[/tex]
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{2.92\times 0.0820 L atm/K mol\times 223K}{0.262atm}=204L[/tex]
Thus volume occupied by 11.7 g of Helium in a balloon is 204L
does a periodic table indicate the occurrence of elements
Answer:
no
Explanation:
it only shows the atomic number and basically the chemical behavior of the element
Step 3: Measure Solubility in Cold Water
10
0
-10
80
100 m
60
-40
20
Temperature of the water to the nearest degree:
ANSWER IS 2°C. !!!
Answer:
2 degrees celcius
Explanation:
In the Lewis dot structure for H2CCH2, how many bonds are between the carbon atoms?
3
4
1
2
Answer:
2
Explanation:
The compound H2CCH2 has the condensed formula C2H4. The name of the compound is ethene. The compound is unsaturated, that is, it contains multiple bonds. The compound has a formula which fits into the general molecular formulae of alkenes (olefins) which his CnH2n.
Olefins have a double bonds between the carbon atoms. That is , the two carbon atoms in Olefins are connected via a double covalent bond. This now implies that the two carbon atoms in ethene (C2H4) are connected by two covalent bonds in the lewis structure of the molecule as is common for Olefins.
In the Lewis dot structure for [tex]\rm H_2CCH_2[/tex], there is one covalent bond present between the carbon atoms. The correct answer is option c.
A dot structure is a method of depicting an atom's valence electrons by placing dots around the atomic symbol. One valence electron is represented by each dot.
In the Lewis dot structure of [tex]\rm H_2CCH_2[/tex], there is one bond between the carbon atoms. This is because each carbon atom has two electrons in its valence shell, and each hydrogen atom has one electron in its valence shell.
The two carbon atoms share two electrons to form one covalent bond, and each carbon atom also shares one electron with a hydrogen atom to form two additional covalent bonds.
Therefore, the correct answer is option c. There is one bond (covalent bond) between the carbon atoms in the Lewis dot structure for [tex]\rm H_2CCH_2[/tex].
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What is the molarity of a solution that contains 2 moles of KCl in 4 L of solution? a 2.0 M b 0.5 M c 0.25 M d 8.0 M
Answer:
A.) 2.0 M
Explanation:
Molarity=mole of solutes/Liters of solution so M=mol/L
2moles/4 L =2 M
) What is the definition of an enzyme? A.Enzymes are carbohydrate molecules that act as catalysts to speed up chemical reactions in living things. B.Enzymes are polymer molecules that act as catalysts to slow down chemical reactions in living things. C.Enzymes are protein molecules that act as catalysts to speed up chemical reactions in living things. D.Enzymes are fat molecules that act as catalysts to speed up chemical reactions in living things. E.Enzymes are protein molecules that act as catalysts to slow down chemical reactions in living things.
Answer:
option c
enzymes are protein molecules that act as catalysts to speed up bio chemical reactions
Which of the following statements is true? Less rain and snow falls in smoky areas than in other areas. Acid rain causes corrision of buildings and statues. The first laws againts pollution were passed in the 1990s. Cars are the leading cause of nitrogen oxide pollution.
Answer:
Acid rain causes corrosion in buildings.
Explanation:
This is true because acid rain over time can eat away at the building.
The density was of a solution of sulfuric acid is 1.285g/cm3 and it is 38.08% (by weight) acid. How many millimeters of the acid solution do you need to supply 125 grams of sulfuric acid?
Answer:
255.5cm³
Explanation:
A solution that is 38.08 % by weight has 38.08g of sulfuric acid per 100g of total solution. Thus, mass of solution you need to obtain 125g is:
125g H₂SO₄ × (100g solution / 38.08g H₂SO₄) = 328.3g of solution
As density of the solution is 1.285g / cm³, the volume of 328.3g is:
328.3g × (1cm³ / 1.285g) = 255.5cm³
Only purple flowers result from a cross between purple-flowered pea plants and white-flowered pea plants. What does this indicate?
Purple flowers are a mutation
Purple flowers are recessive
Purple flowers are dominant
Purple flowers are hybrid
Answer:
Purple flowers are dominant
Explanation:
WILL MARK BRAINLIEST IF GOOD EXPLANATION...
Ethyl acetate is a sweet-smelling solvent used in varnishes and fingernail polish remover. It is produced industrially by heating acetic acid and ethanol
together in the presence of sulfuric acid, which is added to speed up the
reaction. The ethyl acetate is distilled off as it is formed. The equation for the
process is as follows.
CH3COOH + CH3CH2OH --> CH3COOCH2CH3 + H2O
Determine the percentage yield in the following cases:
a. 68.3 g of ethyl acetate should be produced but only 43.9 g is recovered.
b. 0.0419 mol of ethyl acetate is produced but 0.0722 mol is expected. (Hint:
Percentage yield can also be calculated by dividing the actual yield in moles
by the theoretical yield in moles.)
c. 4.29 mol of ethanol is reacted with excess acetic acid, but only 2.98 mol of
ethyl acetate is produced.
d. A mixture of 0.58 mol ethanol and 0.82 mol acetic acid is reacted and 0.46
mol ethyl acetate is produced. (Hint: What is the limiting reactant?)
Answer:
a) 64.27%
b) 58%
c) ethanol is the limiting reactant
d) ethanol is the limiting reactant
Explanation:
We have to note that the expected yield is the theoretical yield while the actual mass or amount of product formed is the actual yield.
a) theoretical yield=68.3g
Actual yield= 43.9 g
Percentage yield= 43.9/68.3 ×100
Percentage yield= 64.27%
b) theoretical yield= 0.0722 moles
Actual yield = 0.0419
Percentage yield= 0.0419/0.0722 × 100
Percentage yield= 58%
c) note that the limiting reactant yields the least number of moles of product
Ethanol will be the limiting reactant since it is not present in excess.
d) from the reaction equation;
1 mole of acetic acid produces 1 mole of ethyl acetate
0.58 moles of ethanol produces 0.58 moles of ethyl acetate
1 mole of acetic acid yields 1 mole of ethyl acetate
Hence 0.82 moles of acetic acid yields 0.82 moles of ethyl acetate
Hence ethanol is the limiting reactant.
For which purpose do biochemist insert human genes into bacteria
Answer: to find a cure for the common cold to produce insulin for diabetics
Explanation: It has helped many people
An acid is added to water, and a new equilibrium is established. What is the system after the acid is added? A. pH w = 1 x 10-14 B. pH w -14 C. pH > pOH and Kw = 1 x 10-14 D. pH > pOH and Kw > 1 x 10-14
Answer:
C. pH > pOH; Kw = 1.0 * 10^-14
Explanation:
The ion product of water, Kw = [H+]*[OH-] = 1.0 * 10^-14. It is a constant.
When an acid or base is added to water, its ion product does not change as it a constant. However, the relative concentrations of H+ ions and OH- ions will change depending on whether an acid or base is added to water.
When an acid is added to water, the concentration of H+ ions increases while that of OH- ions decreases, and vice versa.
Therefore, in the above situation where an acid is added to water, pH > pOH; Kw = 1.0 * 10^-14
explain why an indicator is used in titration
Answer:
Titrations. Because a noticeable pH change occurs near the equivalence point of acid-base titrations, an indicator can be used to signal the end of a titration. When selecting an indicator for acid-base titrations, choose an indicator whose pH range falls within the pH change of the reaction.
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a sample of a compound that contains only the elements C,H and N is completely burned in O2 to produce 44g of CO2, 45g of H2O, and some NO2. A possible empirical formula of the compound is A. CH2N B.CH5N C.C2H5N D.C3H3N2
Answer:
B. CH₅N
Explanation:
The combustion reaction of a compound CₐHₓNₙ with O₂ is:
CₐHₓNₙ + O₂ → a CO₂ + X/2 H₂O + n NO₂
Where 1 mole of CₐHₓNₙ with an excess of O₂ produce a moles of CO₂, X/2 moles of H₂O and n moles of NO₂
Thus, you need to convert the mass of CO₂ and H₂O to moles to find the C:H ratio and determine a possible empirical formula thus:
Moles CO₂ (Molar mass 44g/mol):
44g ₓ (1mol / 44g) = 1 mole CO₂ = 1 mole C
Mole of H₂O (Molar mass 18g/mol):
45g ₓ (1 mol / 18g) = 2.5 moles H₂O = 5 moles H
Thus, in the compound you have 5 moles of H per mole of C, and a possible empirical formula is:
B. CH₅NThe only structure that meet this C:H ratio
The most likely empirical formula for the one that exemplifies a specimen of the compound containing the element C, H, and N which are completely combusted in oxygen to generate 44g Co2, 45g of H2O, and a little NO2 would be:
B). CH₅N
The reaction of combustion taking place in the compound CₐHₓNₙ using [tex]O_{2}[/tex] (oxygen) would be:
[tex]C_{a} H_{x} N_{n} + O_{2}[/tex] → [tex]aCO_{2} + X/2 H_{2}O + nNO_{2}[/tex]
In this reaction, 1 mole belonging to [tex]C_{a} H_{x} N_{a}[/tex] having additional [tex]O_{2}[/tex] (oxygen) leads to generating '[tex]a[/tex]' moles of [tex]CO_{2}[/tex] (Carbon dioxide), [tex]X/2[/tex] number of moles of [tex]H_{2}O[/tex](Hydrogen), and n amount of moles of Nitrogen([tex]N[/tex]).
Therefore, it will be required to transform the mass of [tex]CO_{2}[/tex] and [tex]H_{2}O[/tex] in the form of moles to deduce the ratio C:H to look for the likely empirical formula.
[tex]CO_{2}[/tex] Moles (∵ Molar mass [tex]= 44g/mol)[/tex]
= [tex]44g[/tex] × [tex](1mol/44g)[/tex]
[tex]= 1 mole[/tex] of [tex]CO_{2}[/tex]
[tex]= 1 mole[/tex] of C
[tex]H_{2}O[/tex] Moles (∵ Molar mass =[tex]18g/mol)[/tex]
[tex]= 45g[/tex] ₓ [tex](1 mol / 18g)[/tex]
[tex]= 2.5 moles[/tex] [tex]H_{2}O[/tex]
[tex]= 5[/tex] [tex]moles of H[/tex] because (H * 2)
∵ The C:H ratio is 1:5 implying that formula would include 5 H moles and 1 C mole. So, CH₅N is the correct option.
Thus, option B is the correct answer.
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For neap tides, what must the angular alignment be between the sun, earth and moon?
Answer:
The angular alignment is 90 degrees
Explanation:
The neap tide is a type of tide which occurs around seven days after a spring tide. This type of tide happens twice every month.
The tide is usually moderate and it exists when the sun and moon are usually at right angles to each other when it occurs. A right angle is also known as 90 degrees which validates the tide occurring at an angle 90.
Which represents the greatest time frame in which a short-term environmental change can occur?
in days
O in minutes
O over hundreds of years
O over thousands of years
Answer:
in days
Explanation:
A short term environmental change refers to changes in the environment that happens within a short period of time, for example, flooding, drought, volcanic eruptions etc. In contrast to short term environmental change, long term environmental change takes place over a long period of time hence species have a longer time to adapt to it. Short term environmental changes may or may not be caused by humans. An example of a short term environmental change caused by humans is oil spillage. Short term environmental changes may lead to the the migration of species from the ecosystem.
Short term environmental changes usually occur within a very short time. The greatest time frame in which a short term environmental change can occur is in a matter of days. Only longterm environmental changes span hundreds and thousands of years.
Answer:
it is c
Explanation:
i took the test :)
Which statement accurately describes the movement of Earth’s plates due to convection currents?
Answer:
Volcanic eruptions.
What takes place in a cell's mitochondria ?
A.cellular respiration
B.DNA replication
C.protein synthesis
D.photosynthesis
I NEED HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
c
Explanation:
the mitochodria is the protien power house of the cell
What shape would a molecule with two bound groups and two lone pairs
have?
A. Trigonal pyramidal
B. Tetrahedral
C. Linear
D. Bent
Answer:
It would have to be D, a bent shape
Explanation:
I just took the quiz
1
Net ionic equations remove spectator ions and shows only the chemical species that are involved in the chemical reaction. Write the net ionic equation for the following acid base reaction.
Molecular Equation: 2 HCl (aq) + Mg(OH)2 (aq) → MgCl2 (aq) + 2 H2O (l)
Complete Ionic: 2 H+ (aq) + 2 Cl– (aq) + Mg2+ (aq) + 2 OH– (aq) → Mg2+ (aq) + 2 Cl– (aq) + 2 H2O (l)
Net Ionic Equation: ______________________________________________________
Answer:
The reaction of an acid and a base is called a neutralization reaction. ... However, in the reaction between HCl(aq) and Mg(OH) 2(aq), additional molecules of HCl and ... First, we will write the chemical equation with the formulas of the reactants ... The chloride ions are the only spectator ions I THINKS
Explanation:
Element X is a solid that is brittle, lacks luster,and has six valence electrons. In which group on the Periodic Table would element X be found
Answer:
Sulfur?
Explanation:
Sulfur has 6 valence electrons and does not have luster.
Calculate the Molarity of a 0.23 mole solution of sucrose, C 12 H 22 O 11 that is dissolved in 5 liters of water.
Answer:
0.046 M
Explanation:
Molarity = mol solute/ L solution = 0.23 mol/ 5 L = 0.046 mol/L = 0.046 M
Distillation is a _____________ separation technique.
chemical
physical
Answer:
Chemical
Explanation:
Because it's being done by chemical means
3. Sugar solution(sugar + water) is a homogeneous mixture and sugar can be separated from water through evaporation .Comment.
Plz, answer
Answer:
water is the answer
Explanation:
The sugar and water mix to make sweet water but the sun extracts the sugar from the water leaving only normal water
Answer:
water can be evaporated
Explanation:
the water will be evaporated leaving only the sugar residue behind.
scientists often work on projects for a long time and fail to see sources of error in their research. Which process allows an outside expert to look at the scientist’s project and point to sources of error?
Answer:
Replication
Explanation:
In science, the work of a scientist is regarded as authentic if other experts in other places can follow the same steps as he/she claimed to follow and arrive at the same result.
For example, a scientist in California, United States of America may carry out a research and publish his findings. Another scientist in Christchurch New Zealand following exactly the same procedure is expected to arrive at the same results as the original researcher if there were no errors in the work.
However, where there are disparities in results, the scientist in Newzealand may discover errors that were unknown to the original researcher in the united States. The New Zealand scientist was carrying out a process known as 'replication'. That is, repeating a scientific research in order to obtain the same results thereby validating the research.
A.
B.
C.
D.
what’s the correct answer?
Answer:
C Gamma Rays
Explanation:
Radio waves, on the other hand, have the lowest energies, longest wavelengths, and lowest frequencies of any type of EM radiation. In order from highest to lowest energy, the sections of the EM spectrum are named: *gamma rays* ,X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves.
15. Calculate the hydrogen ion concentration of a
solution whose pH is 2.4
A 3.6 x 0.01
B 2.5 x 0.0001
C 2.5 x 0.01
D 7.0 x 0.01
Answer:
Explanation:
pH = − log [H+] , we can solve for [H+] as,
− pH = log [H+] ,
[H+] = 10^−pH,
so PH =2.4 in you case is
[H+] = 10^-2.4 =0.00398
The option are not correct it looks
4. Why does ammonia, NH3, behave as a base when it reacts with an acid?
A It accepts a neutron and becomes NH3+.
B It accepts a proton and becomes NH4+.
OC It donates a proton and becomes NH2
B is the answer ,ammonium accepts a proton and becomes ammonium ion
Name the process that releases carbon dioxide into the atmosphere.