Answer:
density= mass/volume
hence density of gold rock
= 386/20
=19.3 g/cc
saras car is advertised to get 43 miles per gallon. Sara calculated her gas mileage over the pass month to 39 miles per gallon was Sara's percent yield og gas mileage?
Answer:
Sara's percentage yield of gas mileage is approximately 90.7%
Explanation:
Percentage yield of an process is given by the ratio of the observed, experienced (calculated), or actual yield to the theoretical yield of the process and then multiplying the result by 100%
[tex]Percentage \ yield = \dfrac{Actual \ yield}{Theoretical \ yield} \times 100[/tex]
The theoretical yield of Sara's car is the mileage advertised for the car which the car has 'ideally' which is 43 miles per gallon
∴ The theoretical yield = 43 miles/gallon
The actual yield is the yield of the car Sara is able to calculate, based on how she uses the car which is 39 miles per gallon
∴ The actual yield = 39 miles/gallon
Sara's percentage yield of gas mileage for the car, % yield, therefore is given as follows;
% yield = (39 miles/gallon)/(43 miles/gallon) × 100 ≈ 90.7%
Sara's percentage yield of gas mileage, % yield ≈ 90.7%.
Increase the mass of blue ball. What happens to the force on the red ball? What happens to the force on the
blue ball?
next time put a picture so people can help you more
How many individual atoms are represented in the reactants of the equation shown below?
There are 3 individual atoms are represented in the reactants of the equation.
What is an atom?An atom is a particle of matter that uniquely defines a chemical element. An atom consists of a central nucleus that is surrounded by one or more negatively charged electrons. The nucleus is positively charged and contains one or more relatively heavy particles known as protons and neutrons.
In the reactants given, we have methane which has 2 individual atoms (Carbon and hydrogen) and oxygen has 1 individual atom.
Therefore, There are 3 individual atoms are represented in the reactants of the equation.
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What is the molality of a solution made with 5.6kg of water and 2.11moles of solute?
Answer:
THE MOLARITY IS 2.22 MOL/DM3
Explanation:
The solution formed was as a result of dissolving 37.5 g of Na2S in 217 g of water
Relative molecular mass of Na2S = ( 23* 2 + 32) = 78 g/mol
Molarity in g/dm3 is the amount of the substance dissolved in 1000 g or 1 L of the solvent. So we have;
37.5 g of Na2S = 217 g of water
( 37.5 * 1000 / 217 ) g = 1000 g of water
So, 172.81 g/dm3 of the solution
So therefore, molarity in mol/dm3 = mol in g/dm3 / molar mass
Molarity = 172.81 g/dm3 / 78 g/mol
Molarity = 2.22 mol/dm3
The molarity of the solution is 2.22 mol/dm3
Explanation:
4 Weathering Assessment
2 of 132 of 13 Items
Question
POSSIBLE POINTS: 5.88
On a hot summer day, you and your friend decide to make a drink by mixing ice cubes, water, sugar, and Kool-Aid mix. Which of the following statements best describes what type of change has occurred?
This is an example of chemical change because the sugar dissolved.
This is an example of chemical change because the sugar dissolved.
This is an example of a physical change because the sugar dissolved
This is an example of a physical change because the sugar dissolved
This is an example of a physical change because the ice cubes began to melt.
This is an example of a physical change because the ice cubes began to melt.
This is an example of a chemical change because the Kool-aid dissolved and turned the water red.
Answer:
This is an example of chemical change because the Kool aid dissolved and turned the water red
How many carbon atoms are in 1.25 mol of silver acetate?
The number of carbon atoms present in 1.25 mol of silver acetate is 1.875 × 10²³.
What is Avogadro's number?Avogadro's number is define as the number of atoms of any substance present in one mole of that substance, and it is equal to 6.022 × 10²³, i.e.
1 mole = 6.022 × 10²³ atoms/mol
Given moles of silver acetate = 1.25 moles
Number of atoms of silver acetate in 1.25 moles = 1.25 × 6.022 × 10²³ = 7.5×10²³
Molecular formula of silver acetate is CH₃CO₂Ag, means in this molecule total 8 atoms are present so number of carbon atom will be calculated as:
Carbon atoms = (2× 7.5 × 10²³) / 8 = 1.875 × 10²³ atoms [here we multiply by 2 because 2 atoms of carbon is present in olecule]
Hence required atoms of carbon is 1.875 × 10²³.
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Which of the following preparation of salt is incorrect? *
Acid + alkali
Acid + hydrogen
Acid + carbonate
Acid + metal oxide
Answer:
acid + hydrogen
Explanation:
gives a good combination
Hydrogen and oxygen react under a specific set of conditions to produce water according to the following equation.
2 H2(g) + O2(g) 2 H2O(g)
(a) How many moles of hydrogen would be required to produce 2.8 mol of water?
(b) How many moles of oxygen would be required?
Answer:
fccdsetyujvreettyukknop
Write a balanced equation for the following:
1. P4 + O2 → P2O5
2. C3H8 + O2 → CO2 + H2O
3. Ca2Si + Cl2 → CaCl2 + SiCl4
please let me know if the answer is true or false. if false, please tell me what's false about it. the word that they are wondering if it needs to be changed is highlighted
Answer:
false the answer is woody
Explanation:
those are the two types of stems
2A + N2 -> 2AIN How many moles of aluminum nitride form when 5.00 g of aluminum reacts with excess nitrogen? K 0.0925 mol 0 0.185 mol Oleo mol z se mol
Answer:
0.185 moles of AlN
Explanation:
The equation is:
2Al + N₂ → 2AlN
This reaction indicates that 2 mol of aluminum can react to 1 mol of nitrogen to produce 2 moles of aluminum nitride.
We convert the aluminum's mass to moles
5 g/ 26.98 g/mol = 0.185 moles.
2 moles of Al are needed to produce 2 moles of AlN
so, ratio is 1:1
In conclussion we say:
0.185 moles of Al, must produce 0.185 moles of AlN
a primary means of conveying messages between human
Answer:
The primary means of conveying messages between human are verbal, nonverbal, and visual.
Explanation:
1. Verbal communication depends on words to deliver meaning.
2. Nonverbal communication occurs when meaning or messages are sent or received without the use of words.
3. Visual communication utilizes drawings, illustrations, pictures, colors, graphs, charts, and signs to share meaning.
The verbal method of talking is the primary means of conveying messages among humans.
What makes speaking possible?Speech is spoken language used by people to communicate. The ability to modify voices through the articulation of laryngeal tones into audible oral speech is something that humans have learnt to do, despite the fact that many animals have voices of varied sorts and inflectional capacities.
A bellows-like respiration activator, which provides the driving energy in the shape of an updraft, a phonating sound generator in the larynx (low in the throat), to transform the energy, an audio tunable in the pharynx (higher in the throat), where the independent voice structure is moulded, and a speech-forming device that is connected in the oral cavity represent as the mechanisms for human speech (mouth).
The four structures usually, but not always, work closely together. Toneless whispering can provide audible communication without any voice, and some parts of yodelling that depend on pharyngeal and laryngeal alterations can produce phonation without oral articulation. Lipreading may be accomplished by silent articulation without voice or breath.
Therefore, speech is the primary method of communication among humans.
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What are the steps to balance a chemical equation?
Answer:
Step 1: The Unbalanced Chemical Equation. The unbalanced chemical equation is given to you. ...
Step 2: Make a List. ...
Step 3: Identifying the Atoms in Each Element. ...
Step 4: Multiplying the Number of Atoms. ...
Step 5: Placing Coefficients in Front of Molecules. ...
Step 6: Check Equation. ...
Step 7: Balanced Chemical Equation.
Explanation:
When aqueous solutions of nickel(II) sulfate and ammonium phosphate are combined, solid nickel(II) phosphate and a solution of ammonium sulfate are formed
Answer:
3 NiSO₄(aq) + 2 (NH₄)₃PO₄(aq) ⇒ Ni₃(PO₄)₂ + 3 (NH₄)₂SO₄
Explanation:
The question is missing but I think it must be about writing and balancing the equation.
Let's consider the unbalanced reaction that occurs when aqueous solutions of nickel(II) sulfate and ammonium phosphate are combined to form solid nickel(II) phosphate and a solution of ammonium sulfate. This is a double displacement reaction.
NiSO₄(aq) + (NH₄)₃PO₄(aq) ⇒ Ni₃(PO₄)₂ + (NH₄)₂SO₄
We will start balancing Ni atoms by multiplying NiSO₄ by 3.
3 NiSO₄(aq) + (NH₄)₃PO₄(aq) ⇒ Ni₃(PO₄)₂ + (NH₄)₂SO₄
Now, we have to balance S atoms by multiplying (NH₄)₂SO₄ by 3.
3 NiSO₄(aq) + (NH₄)₃PO₄(aq) ⇒ Ni₃(PO₄)₂ + 3 (NH₄)₂SO₄
Then, we need to balance N atoms by multiplying (NH₄)₃PO₄ by 2. This will be the balanced equation.
3 NiSO₄(aq) + 2 (NH₄)₃PO₄(aq) ⇒ Ni₃(PO₄)₂ + 3 (NH₄)₂SO₄
A sample of Xe gas is observed to effuse through a pourous barrier in 4.83 minutes. Under the same conditions, the same number of moles of an unknown gas requires 2.29 minutes to effuse through the same barrier.
The molar mass of the unknown gas is
_____ g/mol.
Answer:
28.93 g/mol
Explanation:
This is an extension of Graham's Law of Effusion where [tex]\frac{R1}{R2} = \sqrt{\frac{M2}{M1} } = \frac{t2}{t1}[/tex]
We're only talking about molar mass and time (t) here so we'll just concentrate on [tex]\sqrt{\frac{M2}{M1} } = \frac{t2}{t1}[/tex]. Notice how the molar mass and time are on the same position, recall effusion is when gas escapes from a container through a small hole. The time it takes it to leave depends on the molar mass. If the gas is heavy, like Xe, it would take a longer time (4.83 minutes). If it was light it would leave in less time, that gives us somewhat an idea what our element could be, we know that it's atleast an element before Xenon.
Let's plug everything in and solve for M2. I chose M2 to be the unknown here because it's easier to have it basically as a whole number already.
[tex]\sqrt{\frac{M2}{131} } = \frac{2.29}{4.83}[/tex]
The square root is easier to deal with if you take it out in the first step, so let's remove it by squaring each side by 2, the opposite of square root essentially.
[tex](\sqrt{\frac{M2}{131} } )^2= (\frac{2.29}{4.83})^2[/tex]
[tex]{\frac{M2}{131} } = (0.47)^2[/tex]
[tex]{\frac{M2}{131} } = 0.22[/tex]
M2= 0.22 x 131
M2= 28.93 g/mol
2. The diagram shows a Zn/MnO2-KOH alkaline dry cell.
In your response, do the following:
• Label all parts.
• Label the cathode and the anode, including the charges on each.
• Show the flow of electrons.
• Explain how the cell works. Include the oxidation and reduction half-reactions in your explanation.
Answer:
1. Graphite rod (cathode)
2. Positive terminal
3. Solid zinc layer (anode)
4. Paste (reduction takes place here)
5. Negative terminal
Explanation:
This was the only thing i could find on it. hope this helps.
Answer:
Explanation:
• Label all parts.
1. Cathode or Graphite Rod
2. Positive terminal
3. Anode or Solid Zinc layer
4. Electrolyte Paste (reduction takes place here)
5. Negative Terminal (maybe this could also be the Zinc casing)
• Label the cathode and the anode, including the charges on each.
The anode is the zinc layer is negatively charged and the cathode is the graphite rod is positively charged.
• Show the flow of electrons.
The zinc casing is oxidized and the electrons flow along the zinc layer, into the negative terminal, and then out the negative terminal. The electrons move from the wire to the graphite rod. Then from the rod the electrons move to the paste, then the past goes through reduction. The anode gets a negative charge as electrons are released, and the cathode gets a positive charge as the electrons, which are negatively charged, are consumed.
• Explain how the cell works. Include the oxidation and reduction half-reactions in your explanation.
Alkaline dry cells use spontaneous oxidation-reduction reactions to convert chemical energy to electrical energy. According to the lesson ‘’Half-reactions are combined in a small casing, but still separated into half-cells.’’
How many moles of sodium cyanide (NaCN) would be needed to produce
2.1 moles of sodium sulfate (Na2SO4)?
H2SO4 + 2NaCN → 2HCN + Na2SO4
Answer:
4.2 moles of sodium cyanide (NaCN) would be needed to produce 2.1 moles of sodium sulfate (Na₂SO₄).
Explanation:
The balanced reaction is:
H₂SO₄ + 2 NaCN → 2 HCN + Na₂SO₄
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound are necessary:
H₂SO₄: 1 mole NaCN: 2 moles HCN: 2 moles Na₂SO₄: 1 moleThen you can apply the following rule of three: if by stoichiometry to produce 1 mole of sodium sulfate 2 moles of sodium cyanide are necessary, then to produce 2.1 moles of sodium sulfate how many moles of sodium cyanide are necessary?
[tex]amount of moles of sodium cyanide=\frac{2.1 moles of sodium sulfate*2 moles of sodium cyanide }{1 mole of sodium sulfate}[/tex]
amount of moles of sodium cyanide= 4.2 moles
4.2 moles of sodium cyanide (NaCN) would be needed to produce 2.1 moles of sodium sulfate (Na₂SO₄).
Calculate the number of moles in 8200 grams of iron
Can someone help me with this?
Answer:
150 moles (2 sig. figs.)
Explanation:
to convert from ...
grams to moles => divide by formula weight
moles to grams => multiply by formula weight
this problem:
Given mass of Iron (Fe) = 8200g
formula wt of Fe = 56g/mole
moles = mass/formula wt = 8200g / 56g/mol = 146.42857 moles (calculator) = 150 moles (2 sig. figs.)
The number of moles in 8200 grams of iron is 57.69 moles of Fe.
What is Mole concept ?Mole is defined as the amount of the substance containing the same number of discrete entities (atoms, molecules, ions, etc) as there are atoms in a sample of pure 12C weighing exactly 12g.
The number of particles present in one mole of any substance is Avogadro Number and is equals to 6.023 x 10²³ particles.
Given ;
Weight : 8200 grams of ironTo find ;
Mole (n) : ?Formula used :
Mole (n) = given weight / atomic weight= 8200 / 56 (atomic weight of Fe = 56 gm)
= 157.69 moles of Fe.
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What is the main way energy from the Sun moves around Earth?
O
O A.
From the atmosphere
O
B.
From human energy
O
C.
From the ocean currents
Answer:
All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.
How can scientists model the effects of reactant concentration on the speed of a reaction?
A. With a ball-and-stick model
B. With a structural model
C. With a computer model
D. With an atomic model
Answer: it is D
Explanation:
Scientists can model the effects of reactant concentration on the speed of a reaction With an atomic model. Hence, D is correct.
What is an atomic model?Atomic model, in physics, a model used to describe the structure and makeup of an atom. Atomic models have gone through many changes over time, evolving as necessary to fit experimental data. For a more in-depth discussion of the history of atomic models, see atom: development of atomic theory.
Scientists use models to study atoms because atoms are extremely small and can't even be seen. If atoms can't be seen, it's easier to study and predict what atoms will do with a representation of them.
Models are useful tools in learning science which can be used to improve explanations, generate discussion, make predictions, provide visual representations of abstract concepts and generate mental models.
Therefore, Scientists can model the effects of reactant concentration on the speed of a reaction With an atomic model. Hence, D is correct.
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Chemistry help! Please zoom in to see better
Answer:
82.04g
Explanation:
To solve this problem, you need to find the molar mass of HCl, which is the sum of the molar mass of H plus the molar mass of Cl. The molar mass of H is 1.008g/mol while the molar mass of Cl is 35.45g/mol. Thusly the molar mass of HCl is 36.458g/mol. You have 2.25 moles of HCl, so multiply the number of moles by the molar mass to get the mass in g. In this case it is 2.25mol * 36.458g/mol = 82.04g.
If I helped, a brainliest would be greatly appreciated!
Which change is an environmental effect of destroying wetlands?
loss of habitat
less flooding
smog
acid rain
Answer: Trust me 100% plz its loss of habitat wat they said
Explanation:
How many grams of oxygen gas are required to produce 65.75 grams of steam?
2C3H18 (1) + 2502 (g) --> 16CO2 (g) + 18H20 (g) (balanced)
Answer:
The mass of oxygen gas required to produce 65.75 grams of steam is approximately 162.2 grams
Explanation:
From the question, we have the following chemical reaction equation;
2C₃H₁₈(l) + 25O₂ (g) → 16CO₂(g) + 18H₂O (g)
The molar mass of oxygen, O₂ = 32 g/mol
The molar mass of steam, H₂O = 18.01528 g/mol
25 moles of oxygen are required to produce 18 moles of steam
Therefore, according to Proust's law of definite proportions;
(32 × 25) g of oxygen are required to produce (18 × 18.01528) g of steam
65.75 g of steam will be produced by (32 × 25)/(18 × 18.01528) × 65.75 g ≈ 162.2 g of oxygen O₂.
HELPPPP FASTTT! 4. Which is more electronegative?
A. Fluorine
B. Chlorine
C. Bromine
D. Iodine
Explain Your Answer Choice
Answer:
D.lodine
Explanation:
Lodine is a nonsteroidal anti-inflammatory drug . It works by reducing hormones that cause inflammation and pain in the body. Lodine is used to treat mild to moderate pain, osteoarthritis, or rheumatoid arthritis.
I hope it's helpful for you......
WHAT IS THE PH OF LEMON JUICE IF IT HAS A HYDROGEN ION CONCENTRATION [AT]ON[H^ + ]=5.0*10^ -2 M.
Can somebody help me please !!!!!!
Answer:
ph=2
Explanation:
2. How many moles of hydrogen are produced from the reaction of 3.86 moles of zinc with an excess of
hydrochloric acid?
Answer:
as per given balanced equation one mole Zn produces 1mole Hydrogen
when reacted with excess acid.
So 3 moles Zn will give 3moles Hydrogen
Explanation:
According to the balanced chemical equation, one mole of Zn produces one mole of hydrogen . Therefore, 3.86 moles of Zn metal will produce 3.86 moles of hydrogen gas.
What is mole ratio ?Mole ratio refers to the ratio of the number of moles of one substance in a chemical reaction to the number of moles of another substance in the same reaction.
It is derived from the balanced chemical equation for the reaction, which indicates the relative amounts of each substance involved in the reaction.
Mole ratio is important in stoichiometry, which is the study of the quantitative relationships between reactants and products in a chemical reaction.
The given chemical reaction is written as follows:
Zn + 2 HCl ⇒ ZnCl₂ + H₂
According to the balanced chemical equation, one mole of Zn produces one mole of hydrogen . Therefore, 3.86 moles of Zn metal will produce 3.86 moles of hydrogen gas.
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Is NaCl solute or water ?
[tex]plz \: help \: me \: it \: is \: due \: 2moro[/tex]
Answer:
hi.
Explanation:
1. B
2. C
3. A
4. B
5.B
hope this helps
A person has a systolic pressure of 174 mm Hg. What percentage of normal (120 mm Hg) is this?
Answer:
145%
Explanation:
175/12 = 14.5
14.5 * 10 = 145%
A person has a systolic pressure of 174 mm Hg. Then the normal percentage is 145 mm Hg.
What is systolic pressure ?Systolic blood pressure, which is the first number, gauges the pressure in your arteries when your heart beats. Diastolic blood pressure, or the second number, gauges the pressure in your arteries between heartbeats.
Two numbers are used to represent blood pressure values. The highest figure represents the maximal pressure that the beating heart can produce (systolic pressure). The pressure in the arteries between beats is shown by the bottom number (diastolic pressure).
The causes of high systolic blood pressure are numerous. Our arteries tighten as we age, which over time helps to cause high blood pressure. High blood pressure can also be brought on by the genes we inherit. High blood pressure can also result from underlying disorders including thyroid illness, excessive cortisol, and obesity.
Thus, the normal percentage is 145 mm Hg.
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1. A student performed the titration as in this experiment. He transferred a 2.00 mL sample of the
acid into a flask, diluted it with water, and then began to add sodium hydroxide solution from the
buret. After adding 50 mL of NaOH solution, the sample in the flask still had not turned pink.
What error did the student make?
Answer:
The student shouldn't have added water to the acid.
Explanation:
The aim of titration is to standardize an unknown solution. Recall that a standard solution is one whose concentration is known.
After the acid has been prepared, it has a particular concentration. The student should't have diluted it further. The further dilution of a small volume of acid drastically reduces the concentration of the acid to such low value that the H^+ ions present are insufficient to react with the OH^- from base in order to turn the solution to pink.
