Answer:
0.307
Explanation:
use the formula of n=mass /molar mass
Which of the three crowns was made of gold? Explain:
Answer:
I need more context. Maybe add a picture.
Explanation:
Answer:
Crown B
Explanation:
because the density of gold is 19.3 and the density of the crown is 19.29.
Draw molecules that satisfy the following prompts:
1. All molecules must have a minimum of 12 Carbon atoms and exactly 3 heteroatoms (not carbon or hydrogen atoms).
2. You may not use the same molecule twice for any parts of this question.
4. You do not need to look up solubility information, but the answers must be reasonable (supported by the concepts that we have discussed). Also, the structures must be reasonable (improper structures, e.g. carbon with 5 bonds or oxygen with one bond and no charge, will not receive any credit).
a. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M HCl(aq) and dichloromethane.
b. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M NaOH(aq) and dichloromethane.
c. Draw two non-charged molecules that will be separated using neutral water and dichloromethane and in a separatory funnel.
Answer:
see images attached
Explanation:
Here we are trying to perform solvent extraction. In solvent extraction, there must be an aqueous phase and an organic phase.
One of the species to be separated is extracted in greater concentration in the aqueous phase while the other is extracted in greater concentration in the organic phase.
The phase into which each specie is extracted depends on the nature of the specie.
Two structures are shown in the images attached that will be separated by the methods shown in (a) (b) (c) in the question
Reactions are classified as either exothermic or endothermic. . ____________ reactions feel hot (e.g., a burning campfire), whereas _________reactions feel cool.
Answer:
Exothermic reactions feel hot
Endothermic reactions feel cool
Explanation:
In an exothermic reaction, heat is given out by the system. The energy of the reactants is greater than that of the products hence the excess energy is given off as heat. The reaction vessel feels hot.
In an endothermic reaction, the energy of products is greater than that of the reactants hence energy is taken into the system and the reaction vessel feels cool.
__________ have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Answer: have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Explanation:
5. What gases was produced from decomposing hydrogen peroxide? What non-gaseous product formed from the reaction
Answer:
H2O
Explanation:
The equation for the decomposition of hydrogen peroxide is shown below;
2H2O2(l)-----> 2H2O(l) + O2(g)
Hence, the decomposition of H2O2 yields oxygen gas and water. Water is a non gaseous product of the reaction as clearly seen in the equation above.
As temperature decreases, what happens to particles in a material?
Particles become further apart / expand?
Particles become slippery / liquid?
Particles become closer together / contract?
Particles become sticky / plasma?
Answer:
Particles become closer together / contract?
Explanation:
as particles cool down in temp, the particles slow down and compress
Which is an example of a current research focus in chemistry?
A. applying gene therapy to treat certain diseases
B. using hook-and-loop tape in the clothing industry
C. developing smoke detectors for common use
D. studying coal combustion as an energy source
Answer:
b is the correct answer
do not trust answer one
Explanation:
Phosphoric acid, which is commonly used as rust inhibitor, food additive and etching agent for dental and orthopedic use, can be synthesized using a two-step thermal process. In the first step, phosphorus and oxygen react to form diphosphorus pentoxide: P4(l)+5O2(g-2 P20s(g) In the second step, diphosphorus pentoxide and water react to form phosphoric acld P20(9)+3 H200 2H,PO40) Write the net chemical equation for the production of phosphoric acid from phosphorus, oxygen and water.
Answer:
P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)
Explanation:
Phosphoric acid is synthesized using a two-step thermal process.
In the first step, phosphorus and oxygen react to form diphosphorus pentoxide. The corresponding chemical equation is:
P₄(l) + 5 O₂(g) ⇒ 2 P₂O₅(g)
In the second step, diphosphorus pentoxide and water react to form phosphoric acid. The corresponding chemical equation is:
P₂O₅(g) + 3 H₂O(l) ⇒ 2 H₃PO₄(aq)
We can get the net chemical equation by adding the first step, the second step multiplied by 2, and canceling what is repeated on both sides.
P₄(l) + 5 O₂(g) + 2 P₂O₅(g) + 6 H₂O(l) ⇒ 2 P₂O₅(g) + 4 H₃PO₄(aq)
P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)
The table below shows first ionization energies of some of the elements in the periodic table.Based on the information in the table, what can you conclude about the ability of noble gases to undergo ionization?
a
Noble gases give up first electrons easily compared to elements in other groups.
b
Noble gases cannot be forced to give up electrons.
c
The willingness of a noble gas to give up electrons decreases from top to bottom within the group.
d
It is more difficult to remove electrons from a noble gas than it is to remove electrons from elements in other groups.
Answer:
It is more difficult to remove electrons from a noble gas than it is to remove electrons from elements in other groups.
Explanation:
Let me restate here that in the noble gases, the outermost shell is filled. Owing to this full shell, noble gases has the outermost eight electrons required for any specie to attain stability.
It is very difficult to remove an electron from a closed shell. This is why the first ionization energy of noble gases is usually far higher than that of elements from other groups.
What type of energy is defined as the kinetic energy of the atoms of a substance?
Explanation:Thermal energy, or heat, is the energy that comes from the movement of atoms and molecules in a substance. Heat increases when these particles move faster. Geothermal energy is the thermal energy in the earth. Motion energy is energy stored in the movement of objects.
I hope this helped!
When 435 J of heat is added to 3.4 g of olive oil that's at 21 Deg C, it's
temperature increases to 85 Deg C. Calculate the specific heat of Olive oil? Show work
Answer:
k Nishant
Explanation:
i don't know sorry but u can search in google
Particle motion in ice is __________than partlice motion in water.
1. faster
2. slower
3. the same
Answer:
1. Faster
Explanation:
A black object appears black because it reflects all light , and does not absorb any light. True or False
Answer:
False
Explanation:
It is the other way round, a black object appears black because it absorbs all the wavelength of light and does not reflect any light.
A black bucket will appear black because, it absorbs all wavelength of light incident on it. No other wavelength is reflected from the surface of the body. A black color suggests that a body is not reflecting any color. Instead such a body absorbing all the colors. For a white object, they reflect all the wavelength that is incident upon them.how can you tell where sugar enters the blood stream
please help asap
Answer:
Sugar can't enter cells directly , so when blood sugar level rises, ... signal for the release of insulin into the bloodstream.
Explanation:
yes when the sugar enter the bloodstream it may slowly slowly effect in your body and it may causes diabetes
4. CHALLENGE Suppose you had a mixture of sand and small,
hollow beads. How might you separate the mixture?
I'm not sure if this is the answer but maybe oil.
A tree frog uses plants or trees for protection from the rain. The frog is protected from the rain and the tree is neither helped nor harmed
why ice melt into water
You need to make an aqueous solution of 0.192 M barium sulfide for an experiment in lab, using a 500 mL volumetric flask. How much solid barium sulfide should you add?
Answer:
Explanation:
Molecular weight of barium sulphide = 169
500 mL of .192 M barium sulfide = .5 x .192 moles of barium sulphide
= .096 moles of barium sulfide
= .096 x 169 gram of barium sulfide
= 16.22 grams of barium sulfide .
We shall have to add 16.22 gram .
What is the frequency of a wave having 4.90 x 10 -12 J of energy?
Answer:
The answer is
[tex] \huge 7.40 \times {10}^{21} Hz[/tex]
Explanation:
To find the frequency of the wave we use the formula
[tex]f = \frac{E}{h} \\ [/tex]
where
E is the energy
f is the frequency
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question
E = 4.90 × 10-¹² J
So we have
[tex]f = \frac{4.90 \times {10}^{ - 12} }{6.626 \times {10}^{ - 34} } \\ [/tex]
We have the final answer as
[tex]7.40 \times {10}^{21} \: \: Hz[/tex]
Hope this helps you
6. Clownfish, sea anemone, coral, sea urchins, sponges and parrot fish are 5 points
just a few examples of the large variety of organisms that can be found in
a coral reef. The coral reef and its inhabitants (residents) are suffering due
to several factors such as pollution, coastal development, sedimentation
and destructive fishing practices. What would be the most likely result if
some of the species in the coral reef are destroyed? *
Answer:
The orange-and-white clownfish you know from Hollywood is only one of 30 species of clownfish that live in coral reefs around the world; small in size and big in personality, these tiny comedians have one of the most unique lifestyles in the reef. The orange-and-white clownfish you know from Hollywood is only one of 30 species of clownfish that live in coral reefs around the world; small in size and big in personality, these tiny comedians have one of the most unique lifestyles in the reef.
Explanation:
point being, it would be absolutely terrible
Coral reef are the biggest biodiversity in the world. Therefore, destruction of coral reefs definitely affect the aquatic livings. As well as it leads to erosion of seashore lines.
What are coral reefs?Corals reefs are the habitat of 25% of sea organisms. It means there are well over a million species that rely on coral reefs for their existence. The reef offers these organisms the vital food, habitat, and breeding grounds required for the survival of their species.
The marine biodiversity would suffer greatly if their homes vanished. And many fish, turtles, and other species would vanish in a domino-like fashion.
Coral reefs are threatened by a number of things, such as local threats like overfishing, destructive fishing methods, coastal development, pollution, and careless tourism, as well as global effects of climate change like warming seas and rising CO₂ levels in the water. Natural phenomena like hurricanes, El Nio, and diseases are also a threat to oral reefs.
Find more on coral reefs:
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Identify the correct net ionic equation for the reaction that occurs when solutions of Pb(NO3)2 and NH4Cl are mixed.
Answer:
Pb2+(aq) + 2Cl–(aq) ----> PbCl2(s)
Explanation:
The net ionic equation shows the main reaction that takes place in a system. Hence, a net ionic equation focusses only on those species that actually participate in the reaction.
For the reaction between Pb(NO3)2 and NH4Cl , the net ionic equation is;
Pb^+(aq) + 2Cl^-(aq) ---> PbCl2(s)
The correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)To know the the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed, we shall write the net ionic equation for the reaction. This is illustrated below:
Pb(NO₃)₂(aq) —> Pb⁺(aq) + NO₃¯(aq)
NH₄Cl(aq) —> NH₄⁺(aq) + Cl¯(aq)
Pb(NO₃)₂(aq) + NH₄Cl(aq) —>
Pb⁺(aq) + NO₃¯(aq) + NH₄⁺(aq) + Cl¯(aq) —> PbCl₂(s) + NO₃¯(aq) + NH₄⁺(aq)
Cancel the spectator ions (i.e NO₃¯ and NH₄⁺) and write 2 before Cl¯ to obtain the net ionic equation as shown below:
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Thus, the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Learn more: https://brainly.com/question/21883718
3 points
18) A student determines the density of gold to be 20.9g/L. The true
density of gold is 19.30g/L. What is the student's percent error?round
answer to 2 significant figures *
Answer:
The answer is 8.29 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
actual density = 19.30g/L
error = 20.9 - 19.3 = 1.6
We have
[tex]p(\%) = \frac{1.6}{19.3} \times 100 \\ = 8.290155440...[/tex]
We have the final answer as
8.29 %Hope this helps you
In which atmospheric layer is the ozone layer?
A.troposphere
B.mesosphere
C.stratosphere
D.thermosphere
Answer:
stratosphere
Explanation:
contains a high concentration of ozone in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.
Answer:
stratosphere
Explanation: Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface. Ozone is a molecule that contains three oxygen atoms.
The data table shows the number of pumpkin seeds that germinate at different temperatures. What is the median number of seeds that germinate at 24C?
A. 80.5 B. 82 C. 78.5 D. 80
Answer:
Explanation:
80
Discuss the relationship between atoms, elements and compounds. Include in your discussion if these are mixtures or pure substances and why.
Answer:
Elements are the simplest complete chemical substances. Each element corresponds to a single entry on the periodic table. An element is a material that consists of a single type of atom. Each atom type contains the same number of protons.
Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds.
Explanation:
On average, about ____________ of incoming solar radiation is reflected back to space.
A 50%
B 30%
C 20%
D 10%
Use the drop-down menu to complete the statement.
Atoms of elements in the same group have the same number of
. This is why they have similar chemical properties.
Answer:
valence electrons
Explanation:
other guy was close enough
Atoms of elements in the same group have the equal number of valence electrons. That is why they have similar chemical properties.
Why does the element in the same group have similar chemical behavior?The chemical properties of elements depend on the number of valence electrons in their outermost shell. Those elements which are placed in the same group in the periodic table have the same number of valence electrons.
Therefore, elements present in the same group of the modern periodic table have similar chemical behavior.
The elements having a similar valence shell electronic configuration in their atoms are arranged in the same group of the periodic table. These valence electrons decide the chemical properties and reactivities of the chemical elements.
For example, all the elements in group 1 of the periodic table have one electron in their valence shell and all the elements present in group 17 have seven electrons in their valence shell.
Learn more about elements with similar chemical behavior, here:
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If 0.4743 moles of H2O are produced, how many grams of VOCl3 will also be produced?
(V2O5 + 6 HCl → 2 VOCl3 + 3 H2O)
Answer:
i hope this helps. sorry if it totally doesn't
Plz answer me will mark as brainliest
Answer:
Compared to the walls of the right ventricle, the walls of the left ventricles are much thicker.
The plasma carries hormones, which are the body's chemical messengers.
____ KClO3 = ____ KCl + ____ O2
Answer:
2KCIO3=2KCI+3O2
Explanation:
1. equalize right side O with left side O- Right side we have 3 and left only 2 so we add 3 in front(on left side)(3*2=6 O on both sides)
2.we add 2 on right side so now we have 6 O on left and 6 O on right and 2KCI
3.Add 2 on right side KCI so on both sides we got 2 KCI