Answer:
copper oxide has been reuced into copper
Explanation:
The copper has gained electrons to become stable on its own without oxygen
OILRIG- show that reducution is the gain of electrons
Students in Ms. Brown demonstrated several chemical reactions but the data did not represent the law of conservation of matter in
any of the four experiments. Kai and Maria are about to add 3 grams of magnesium (Mg) to a test tube of 30 grams of hydrochloric
acid (HCI). They covered their container with a balloon as a seal. If the girls expect a chernical change as well as evidence of the
Law of conservation of matter, choose ALL of the predictions that are appropriate?
A)
There will be a rapid evolution of gas.
B)
The mass of the products will equal 339.
The solid magnesium metal will disappear.
D)
The balloon covering the container will expand.
E)
There will be a dramatic change in temperature,
Answer:
Answer: everything except E
Explanation: There was no dramatic change in temperature and i just took the assignment.
According to the law of conservation of matter, matter cannot be created not be destroyed. In this experiment, no matter loss will occur but there will be rapid evolution hydrogen gas and the balloon will expand.
What is conservation of matter?According to conservation of matter, matter can neither be created nor be destroyed but its state and properties can be changed. The total mass of the reactants will be equal to the total mass of the products.
Magnesium is a second group element and is a metal. Metal reacts with hydrogen halides to form metal halides and hydrogen gas as the reaction written below:
[tex]Mg +2 HCl \rightarrow MgCl_{2} +H_{2}[/tex]
The evolved hydrogen gas in this reaction tries to diffuses out the sealing and thus the balloon cover expands. And thus the solid magnesium metal disappears to form magnesium chloride.
The evolution of gases is exothermic and therefore, the temperature outside increases suddenly. There we can see bubbles of hydrogen in the reaction system.
Therefore, the changes that occur in the experiments are, rapid evolution of gases, solid metal disappears, sealing cover expands and there occur a rapid change in temperature. Thus options A,C,D,E are correct.
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2) A student determined the melting point of a substance to be 55.2DC. If the accepted value
is 50.1C, what is the percent error in the student's determination?
A) 12.0 B) 5.10 C) 10.2 D) 9.24
Answer:
C) 10.2
Explanation:
Formula: Actual-Expected/Expected
The actual was 55.2 while the expected was 50.1
55.2-50.1/50.1=0.101796407 * 100= 10.2%
The percentage error in the student's determination is 10.2%
The correct answer to the question is Option C. 10.2
From the question given above, the following data were obtained:
Measured value = 55.2 °C
Accepted value = 50.1 °C
Percentage error =?Next, we shall determine the absolute error. This can be obtained as follow:
Measured value = 55.2 °C
Accepted value = 50.1 °C
Absolute error =?Absolute error = |Measured – Accepted|
Absolute error = |55.2 – 50.1|
Absolute error = 5.1Finally, we shall determine the percentage error.
Absolute error = 5.1 °C
Accepted value = 50.1 °C
Percentage error =?[tex]Percentage error = \frac{Absolute error }{Accepted value} * 100\\\\= \frac{5.1}{50.1} * 100\\\\[/tex]
Percentage error = 10.2%Therefore, the percentage error in the student's determination is 10.2%.
The correct answer to the question is Option C. 10.2
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Which of the following do not have a nucleus? *
bacteria
virus
both bacteria and viruses do NOT have a nucleus
both bacteria and viruses DO have a nucleus
Answer:
C
Explanation:
bacteria and virus do not have nucleas. so C
if my answer helps please mark as brainliest.
1 How does a hydroelectric plant work to produce electricity? List the steps below.
2 How is the way that a wind turbine works similar to the way that a hydroelectric
plant works? How is it different?
Answer:
1. -Hydropower plants capture the energy of falling water to generate electricity
-a turbine converts the kinetic energy of falling water into mechanical energy.
- a generator converts the mechanical energy from the turbine into electrical energy.
2. In the case of a wind-electric turbine, the turbine blades are designed to capture the kinetic energy in wind. The rest is nearly identical to a hydroelectric setup: When the turbine blades capture wind energy and start moving, they spin a shaft that leads from the hub of the rotor to a generator.
Explanation:
hope this kinda helped.
2Na(s) + Cl2(g) → 2NaCl(s)
Which of the following choices shows the correct Lewis electron-dot diagram for a molecule of chlorine, Cl2?
Answer: 2!
Explanation:
The best lewis structure for [tex]Cl_2[/tex] is in option 2.
Na or sodium is the cation in the reactant.
Cl or chlorine is the anion in the reactant side.
NaCl is the product of the reaction.
Lewis Structure is a very simplified representation of the valence shell electrons in a molecule. It is used to show how the electrons are arranged around individual atoms in a molecule. Electrons are shown as "dots" or for bonding electrons as a line between the two atoms.
Chlorine is a group VIIA element in the periodic table and contains seven electrons in its last shell.
Valence electrons are given by chlorine atoms = [tex]7\times2=14[/tex]
Total valence electrons = 14
So, each of Cl is surrounded by three pairs of dots, connected by a single line. So, the best lewis structure for [tex]Cl_2[/tex] is in option 2.
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Salinity affects density. Choose all of the correct answers.
options:
As water temperature decreases, water density increases.
As water temperature increases, water density increases.
As concentration of salt increases, water density also increases.
As concentration of salt decreases, water density also increases.
Answer:
1 and 3 i think so i could be wrong
Salinity affects density in the following instances:
A. As water temperature decreases, water density increases.
C. As concentration of salt increases, water density also increases.
What is salinity?Salinity can be defined as a measure of the amount of salt that is dissolved in a water body. Thus, it mainly measured in gram per liters.
What is density?Density can be defined as mass per unit volume. Also, it is measured in kilogram per cubic meters.
Based on scientific records, salinity affects density in the following instances:
As the temperature of water decreases, the volume increases and as such water density increases.As concentration of salt increases, water density also increases due to an increase in the mass of the water.Read more on salinity here: https://brainly.com/question/20283396
how do you identify an acid from its chemical formula
the more massive an object is, the more
Answer:
it have more more mass, gravitational potential energy
Explanation:
hey y’all, I’m growing a plant for science class but I need some questions about the plant, can someone please give me atleast 3 questions to answer for it..
Hurry pls <3
Answer:
What four things do all plants need?
What are the parts of the plant?
What does the root do for the plant?
What does the stem do for the plant?
What do leaves do for the plant?
The plant parts that take in water and minerals from the soil are?
What is the first stage in the growth of many plants?
Explanation:
:)
if a sample of 4.50 moles of hydrogen gas was reacted with excess nitrogen, how many moles of ammonia gas would be produced?
Answer: 3.00
Explanation: got the answer from my teachers notes
According to stoichiometry, if a sample of 4.50 moles of hydrogen gas was reacted with excess nitrogen, 3 moles of ammonia gas would be produced.
What is stoichiometry?Stoichiometry is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.It is useful in balancing chemical reactions.In the given reaction 3 moles hydrogen gives 2 moles ammonia, thus, 4.5 moles of hydrogen will give, 4.5×2/3=3 moles.
Thus, if a sample of 4.50 moles of hydrogen gas was reacted with excess nitrogen, 3 moles of ammonia gas would be produced.
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Which of the following describes an adaptation?
A. a place where an organism lives
B. something that does not help an organism survive
C. something that improves an organism's ability to survive
D. a part of the animal's life cycle
Answer: C something that improves an organisms ability to survive
Answer:
C.
Explanation:
what is law of conservation of mass
Answer:
Mass in an isolated system can neither be destroyed nor created.
Explanation:
In a chemical reaction, mass can neither be created nor be destroyed.
What types of chemical
reactions can change a toxic
chemical into one that is less
toxic
Answer:
Very toxic materials are substances that may cause significant harm or even death to an individual if even very small amounts enter the body.There are a number of very toxic materials that may be used in workplaces. Some examples include carbon monoxide, hydrogen sulfide, chlorine and sodium cyanide
Explanation:
here are generally four types of toxic entities; chemical, biological, physical and radiation: Chemical toxicants include inorganic substances such as, lead, mercury, hydrofluoric acid, and chlorine gas, and organic compounds such as methyl alcohol, most medications, and toxins.
The highly toxic chemical compounds can be changed to less toxic one by suitable substitution reactions where, a functional group which less hazardous but having the same biochemical properties are substituted for the new product.
What is toxicity?Toxicity of a chemical is its ability to cause serious health risks which can strike a single cell. Exposure to toxic chemicals may even lead to death. The dose of toxicity depends on the structure and reactivity of the chemicals.
Also the adverse effect of each toxic chemicals depends on the way of exposure, and the amount of exposed chemical. There are some methods to detoxify a living body if any toxic is intaken. Suitable antidotes are given for them.
The toxicity generated in a chemical might be originated from a certain structure or group. Thus, by altering that group for instance substituting a ring or removing them ir substituting a functional group that is responsible for the toxicity will make the chemical less toxic.
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What happens to the air temperature if you add extra CO2?
Answer:
Adding more CO2 to the atmosphere will cause surface temperatures to continue to increase. However, more energy is absorbed in the weaker bands and in the wings of the strong band, causing the surface and lower atmosphere to warm further.
3. How many grams of water will be produced from 15.0 grams of Methane? *
CH4 +2 02 → CO2 + 2H2O
How many moles are in 15.62g of P?
Answer:
[tex]\boxed {\boxed {\sf 0.5043 \ mol \ P}}[/tex]
Explanation:
To convert from moles to grams, we must use the molar mass. This is found on the Periodic Table. Look for Phosphorous or P.
Phosphorus (P): 30.973762 g/molWe can use this number as a ratio.
[tex]\frac{30.973762 \ g \ P }{1 \ mol \ P}[/tex]
Multiply by the given number of grams: 15.62
[tex]15.62 \ g \ P *\frac{30.973762 \ g \ P }{1 \ mol \ P}[/tex]
Flip the fraction so the grams of phosphorus cancel.
[tex]15.62 \ g \ P *\frac{1 \ mol \ P}{30.973762 \ g \ P }[/tex]
[tex]15.62 *\frac{1 \ mol \ P}{30.973762 }[/tex]
[tex]\frac{15.62 \ mol \ P}{30.973762 }[/tex]
Divide.
[tex]0.504297799 \ mol \ P[/tex]
The original measurement of grams has 4 significant figures, so our answer must have the same.
For the number we calculated, that is the ten thousandth place. The 9 in the hundredth thousandth place tells us to round the 2 to a 3.
[tex]0.5043 \ mol \ P[/tex]
There are 0.5043 moles of phosphorus in 15.62 grams.
What are the number of atoms in gallium
Answer: 31! hope this helps!
Explanation:
Electrons can occur only in specific
Answer: Electrons have wavelike motion and are restricted to certain energy states associated with specific wavelengths.
An isotope of an element has 95 protons and 146 neutrons. What is the symbol for this
element?
Answer:
238 is the answer
Explanation:
238 - 146 + 3 = 95
Americium (95Am) is an element that has 95 protons and 146 neutrons in its nucleus of an atom.
What is Americium (95Am)?Americium is an element that has 95 protons and 146 neutrons. Its symbol is Am. Its atomic mass is 241 amu which is get by addition of proton and neutron.
So we can conclude that Americium (95Am) is an element that has 95 protons and 146 neutrons in its nucleus of an atom.
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20 points to whoever can answer these 3 questions correctly
Pt. 3
Answer:
Explanation:
You can't award 20 points once you have awarded 5.
One
2K + Cl2 ==> 2KCl
It's True
There are 2 Ks and Cl2 has 2 atoms making up on the left.
On the right, 1 molecule of KCl has 1 Potassium and 1 Cl. But there are 2 molecules so between the two of them, there's 2 Potassiums and 2 Cl
Two
The reactant side is the Left side. Cl2 means there are 2 Cl atoms making Cl2. Answer B
Three
False: There are 2 but read below.
I really don't know how to answer that. It's not qualified enough. There are a total of 2 Chlorines on the right hand side when there are 2 molecules. I think you are intended to answer False, but don't be surprised if you get it wrong.
An atom that has lost one or more electrons is a(n) _____.
Not Cation
Answer:
ion
Explanation:
that is the definition according to g o o g l e:
"an atom or molecule with a net electric charge due to the loss or gain of one or more electrons."
Answer:
An ION
Explanation:
Because a positive ion is called a CATION and a negative ion is called an ANION (Please brainlist me)
Powdered sodium carbonate reacts with a solution of sulphuric acid (H2SO4) to make a solution of sodium sulphate and water
carbon dixide is given
off.
Answer:
yes
Explanation:
Na2CO3 + H2SO4 --> Na2SO4 + H2O + CO2
what are the the examples of amphoteric oxide
Answer:
Many metals (such as zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Amphoterism depends on the oxidation states of the oxide. Al2O3 is an example of an amphoteric oxide.
Answer:
Lead (II) oxide and zinc (II) oxide
Name a non-metal used to make electrode in the cell.
Answer:
graphite
Explanation:
graphite is also good conductor of electricity
4 Al + 3 O2 -> 2 Al2O3 How much aluminum would be needed to completely react with 45 grams of Oz?
Answer:
50.6g Al would be needed
Explanation:
Based on the reaction:
4Al + 3O₂ → 2Al₂O₃
4 moles of aluminium react with 3 moles of oxygen to produce 2 moles of Al₂O₃
To solve this question we need to find the moles of 45g of O₂. Then using the chemical equation find the moles of Al and its mass:
Moles O₂ -Molar mass: 32g/mol-:
45g O₂ * (1mol / 32g) = 1.41 moles O₂
Moles Al:
1.41 moles O₂ * (4mol Al / 3mol O₂) = 1.875 moles Al
Mass Al -Molar mass: 26.98g/mol-:
1.875 moles Al * (26.98g / mol) =
50.6g Al would be needed
The amount of aluminum that would be required to completely react with 45 grams of O2 would be 50.59 grams.
From the balanced equation of the reaction:
[tex]4 Al + 3 O_2 ---> 2 Al_2O_3[/tex]
The mole ratio of Al to O2 is 4:3.
Mole of 45 grams of O2 = mass/molar mass
= 45/32
= 1.4063 moles
Equivalent mole of Al: 4 x 1.4063/3
= 1.875 moles
mass of Al = mole x molar mass
= 1.875 x 26.98
= 50.59 grams
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what is the percent of just the oreo(out of 100%) from the total mass of these 3 cookies combined
Answer:
Percent mass of oreo = 35.11%
Explanation:
Given:
Mass of oreo = 17.1
Mass of 1st cookie = 16.2
Mass of 3rd cookie = 15.4
Find:
Percent mass of oreo
Computation:
Total mass = Mass of oreo + Mass of 1st cookie + Mass of 3rd cookie
Total mass = 17.1 + 16.2 + 15.4
Total mass = 48.7
Percent mass of oreo = [Mass of oreo/Total mass]100
Percent mass of oreo = [17.1 / 48.7]100
Percent mass of oreo = 35.11%
What will happen when iodine solution is added to a solution of potassium bromide?
A)No reaction
B)Solid iodine is produced
C)Bromine is produced
Answer:
C) Bromine is produced
Explanation:
When iodine chemically reacts with potassium bromide then it will lead to the formation of potassium iodide and bromine. This reaction is actually a single displacement reaction in which bromine from potassium bromide is displaced by iodine atom.
When iodine solution is added to potassium bromide solution ,bromine is produced. It is an example of displacement reaction.
What are displacement reactions ?
Displacement reactions are chemical reactions in which one element present in a compound is replaced by another element.The reaction generally takes place between a molecule and a compound.
During the reaction, the anion of compound is replaced by the molecule and the anion of the compound is transformed into a molecule.When iodine molecule in form of solution is reacted with solution of potassium bromide solution of potassium iodide is obtained.
During this reaction anion of potassium bromide that is bromine is replaced by iodine forming solution of potassium iodide and molecule of bromine is liberated in the form of gas.
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Which coefficient placed before HCl will balance the following
equation? Zn+HCI ZnCl2 + H2
Explanation:
Given chemical equation
Zn + HCL ➡ ZnCl2 + H2
Now balancing
Zn + 2HCL ➡ ZnCl2 + H2
Hope it will help :)❤
The coefficient placed before HCl which makes the equation to be balanced is 2.
To know which coefficient will be placed before HCl to balance the equation, we shall simply balance the equation given from the question.
Zn + HCl —> ZnCl₂ + H₂
The above equation can be balance as illustrated below:
There are 2 atoms of H on the right side and 1 atom on the left side. It can be balance by writing 2 before HCl as shown below:
Zn + 2HCl —> ZnCl₂ + H₂
Now, the equation is balanced.
From the balanced equation above, the coefficient written before HCl which makes the equation to be balance is 2.
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A temperature of 37C is equivalent to a temperature of
Answer:
98.6 Degrees Fahrenheit
Explanation:
To convert from Celsius to Fahrenheit, the formula is F=(1.8*C)+32. Since C=37 in this case, our formula is F=(1.8*37)+32. First, solving the work in the parentheses, 1.8*37=66.6. Adding that will get you to 98.6, so F=98.6.
2) Where is Earth, exactly? Use this image to find our location. Earth is
Located in the
A) Norma arm
B) Outer arm
C) Orion spur.
D) Galactic bar
Answer:
C) Orion spur.
The Orion Arm is a minor spiral arm of the Milky Way Galaxy that is 3,500 light-years across and approximately 10,000 light-years in length, containing the Solar System, including Earth.
