Explanation:
Na=23
cl2=35.5×2=71
NaCl=23+35.5=58.5
2Na + Cl2== 2NaCl
2. : 1
20/23=2(x)/71
(71×20)/(23×2)=x
x=30.87g
1:Which example is not a physical change?
2: Which of the following is not a clue that a chemical reaction is taking place?
What is indicated by the prop- prefix?
Answer:
The molecule has 3 carbon atoms.
Explanation:
What is one element that is not found in the human body, air, or the universe ?
Explanation:
For the moment we have analyzed the physical point of view. For many, the most common way to analyze your body is through the chemical elements.
This increases the number of building blocks to more than four particles, but considering that the number of atoms in a 70 kilogram body is 7,000 quadrillion (you write a 7 followed by 27 zeros), it is still quite simple that we can count the 99.95% of your body weight with only seven elements.
The provocative alternative theories to the Big Bang that state that the universe has no limits
You may have heard that most of our body is water. It may seem unlikely given how solid our bodies feel, but most of you are made of cells filled with water.
There is enough structure that you are unlikely to slide down the drain, but you do have a lot of water. About 60 percent of your body is water, even your bones are roughly 30% water.
Two skeletons sitting on the beach.
IMAGE SOURCE, GETTY IMAGES
Caption,
The bones have 30% water in their composition.
Knowing that water is made up of hydrogen and oxygen (H2O), it seems clear to point out that the elements most present in the body are hydrogen and oxygen.
But there is also much of the most versatile of atoms, carbon. All life we know incorporates water and is based on carbon structures.
Since carbon atoms weigh 12 times more than hydrogen atoms, carbon ranks second by weight behind oxygen.
The thing would be like this: we have 65% oxygen, 18% carbon and 10.2% hydrogen.
If we add a small amount of nitrogen (3.1%), a pinch of calcium for those bones (1.6%), 1.2% of phosphorus, 0.25% of potassium and sulfur and smaller percentages of sodium, magnesium and chlorine, we already reached 99.95
Explain the term pycnocline
Answer:
It is a Cline or layer where density gradient is greatest within a body of water
Which of the following are elements in this equation: 2H2O2 (aq) → 2H2O (l) + O2 (g)?
Check all that apply:
A. O
B. g
C. Aq
D. H
2.0 L of oxygen gas and 8.0 L of nitrogen gas at STP are mixed together. The gaseous mixture is compressed to occupy 2.0 L at 298 K. What is the pressure exerted by this mixture?
Answer:
5.5 atm
Explanation:
Step 1: Calculate the moles in 2.0 L of oxygen at STP
At STP, 1 mole of an ideal gas occupies 22.4 L.
2.0 L × 1 mol/22.4 L = 0.089 mol
Step 2: Calculate the moles in 8.0 L of nitrogen at STP
At STP, 1 mole of an ideal gas occupies 22.4 L.
8.0 L × 1 mol/22.4 L = 0.36 mol
Step 3: Calculate the total number of moles of the mixture
n = 0.089 mol + 0.36 mol = 0.45 mol
Step 4: Calculate the pressure exerted by the mixture
We will use the ideal gas equation.
P × V = n × R × T
P = n × R × T / V
P = 0.45 mol × (0.0821 atm.L/mol.K) × 298 K / 2.0 L = 5.5 atm
Which of the following is a true statement regarding living organisms? All living things- (A. Require oxygen to breath)
(B. Are capable of intelligent thought)
(C.are made up of one or more cells)
(D.have a lifespan of at least on weak?
Answer:
A or C
Explanation:
Answer:
are made up of one or more cells
Explanation:
A cell is the building block of life of any organism. Therefore, an organism simply cannot exist if it has no cells
Therefore, the independent variable was _____ and the dependent variable was _____
sugar concentration
pressure
solubility
temperature
Answer:
temperature and solubility
Explanation:
In the experiment where we are testing the solubility of sugar at different temperatures and pressure, the dependant variable is the solubility and the independent variables are the temperature, pressure and sugar concentration.
What is independent variables ?Independent variables in an experiment is the variables which does not depends on any other variables and on which we can have access or control.
Dependant variables are dependant on the independent variables and they change with respect to the change in independent variables. On dependant variables are those which we are studying and can have no direct control over it,
In the solubility measurement, solubility is the dependant variable and the we are measuring it under different conditions that are the independent variables such as temperature, pressure, sugar concentration etc.
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What is the name of the process scientists use to give different names to different organisms?
astronomy
economy
identification
taxonom
Answer:
D). Taxonomy.
Explanation:
'Taxonomy' is described as the process or the science of finding, describing, classifying, and naming different organisms. It is characterized as the technique of classification of animals, micro-organisms, plants, etc. into different categories or hierarchies. It has primarily been divided into eight distinct types like kingdom, species, order, family, etc.
Astronomy is associated with the study of the physical universe while the economy is defined as the study of efficient utilization of resources and identification is the process of recognizing an object. Thus, option D is the correct answer.
which of the following systems of equilibrium is not affected?
Answer:
The first one
Explanation:
Both the products and reactants in the first equation have the same number of moles and will not be affected by a change in volume.
Would a burning candle have potential or kinetic energy?
Answer:
When the candle is lit and burning, it has kinetic energy.
Explanation:
please smash brainliest on my doorstep
Plz answer fast Name the four parts of a circuit.
Answer:
A switch
Battery or cell
Resistor
Rheostat
Appliance or load such as bulb
connecting wires.
Jockey
Inductor
Capacitor
Meter bridge
Potentiometer
Voltimeter
Ammeter
Galvanometer
How could renewable energy sources be used to heat and cool a house?
Aluminum chloride, AlCl3, is an inexpensive reagent used in many industrial processes. It is made by treating scrap aluminum with chlorine according to the following equation. Please balance the equation.
__2_ Al (s) + 3___ Cl2(g) _2___ AlCl3(s)
If you start with 3.11 g of Al and 5.32 g of Cl2, which reagent is limiting? How many grams of AlCl3 can be produced? During an experiment you obtained 5.57 g of AlCl3, what was your percent yield?
Answer:
Cl₂ the limiting reactant.
6.67g of AlCl₃ can be produced.
83.5% is percent yield
Explanation:
Based on the reaction:
2 Al + 3Cl₂ → 2AlCl₃
2 moles of aluminium react with 3 moles of chlorine.
To solve this question we must find the moles of each reactant in order to find limiting reactant. With limiting reactant we can find theoretical yield. Percent yield is:
Actual yield (5.57g) / Theoretical yield * 100
That means if we find theoretical yield we can find percent yield:
Moles Aluminium: 26.98g/mol
3.11g * (1mol / 26.98g) = 0.115 moles Al
Moles Chlorine: 70.90g/mol
5.32g * (1mol / 70.90g) = 0.075 moles Cl₂
For a complete reaction of 0.075 moles of Cl₂ are required:
0.075 moles Cl₂ * (2mol Al / 3mol Cl₂) = 0.050 moles of Al
As there are 0.115 moles of Al, Aluminium is the excess reactant and Cl₂ the limiting reactant.
Moles AlCl₃ and mass: 133.34g/mol
0.075 moles Cl₂ * (2mol AlCl₃ / 3mol Cl₂) = 0.050 moles of AlCl₃
0.050 moles of AlCl₃ * (133.34g / mol) =
6.67g of AlCl₃ can be producedPercent yield:
5.57g / 6.67g * 100 =
83.5% is percent yieldFind the number of grams of calcium chloride needed to prepare 500.0ml of a 4.0m solution
Answer:
222 g
Explanation:
First we convert 500.0 mL to L:
500.0 mL / 1000 = 0.500 LThen we use the definition of molarity to calculate how many calcium chloride moles are required:
Molarity = moles / litersMolarity * liters = moles4.0 M * 0.500 L = 2.00 molNow we convert 2.00 moles of calcium chloride into grams, using its molar mass:
2.00 mol * 111 g/mol = 222 gWhich type of molecule is shown below? I CH3 C=C H CH3 O A. Alkene O B. Cyclic alkane O C. Alkane O D. Alkyne
Answer:
Alkene
Explanation:
Took the test.
The correct answer is Option (A) Alkene.
What is Alkene?Alkenes are the hydrocarbon which contain double bond of carbon and carbon.The general formula of alkene are CnH2n.Alkenes are unsaturated hydrocarbons. Why other options are incorrect?The other options are incorrect because the structure given in the question is C4H8. The IUPAC name of the structure is is 1- butene .The structure describes the general formula of alkene CnH2n where we can say that n= 4Hence , Option (A) is correct and rest options are incorrect.Learn more about Alkenes below
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5. If 4 moles of nitrogen gas reacts with excess hydrogen gas, how many moles of NH3 will be produced?
Be sure to balance the equation first.
__N2 + __ H2 → __ NH3
a. 8 moles NH3
b. 4 moles NH3
C. 2 moles NH3
d. 12 moles NH3
Which example of regeneration is also considered reproduction?
Explanation:
Regeneration is a type of asexual reproduction in which the organism is capable of regrowing certain body parts.
Answer: Regeneration is defined as organism's ability to regrow damaged or lost body parts. It is a type of asexual reproduction which is shown by many fully differentiated organisms. Organism such as Hydra uses regenerative cells for reproduction in the process of budding. The young Hydra gets its nourishment from the parent.
Explanation:
What must be true about the matter at the start of a fire versus the end?
Explanation:
Three things are required in proper combination before ignition and combustion can take place---Heat, Oxygen and Fuel. There must be Fuel to burn. There must be Air to supply oxygen. There must be Heat (ignition temperature) to start and continue the combustion process.
state two applications of simple distillation of separating mixture
Answer:
Purify drinking water of unwanted
chemicals andminerals such as salt.Hope this helps! :D
NaOH dissociation equation
Answer:
This can be represented by the chemical equation: NaOH H2O→ OH- + Na.
Place these elements in order of increasing ionization energy and JUSTIFY A REASON FOR THIS TREND. C Ge Pb Si Sn
Answer: The given elements are arranged in order of increasing ionization energy as Pb < Sn < Ge < Si < C.
Explanation:
The amount of energy required to remove a loosely bound electron from an isolated neutral gaseous atom is called ionization energy.
Larger is the size of an atom more easily it will lose its valence electrons. Hence, less will its ionization energy.
Whereas smaller is the size of an atom more energy will be required to pull out the electron. Hence, more will be its ionization energy.
This means that on moving down a group ionization energy decreases and on moving along a period from left to right the ionization energy decreases.
The given elements are C, Ge, Pb, Si, and Sn. All these elements belong to group 14 of the periodic table.
Therefore, these elements are arranged in order of increasing ionization energy as follows.
Pb < Sn < Ge < Si < C
Thus, we can conclude that given elements are arranged in order of increasing ionization energy as Pb < Sn < Ge < Si < C.
A mixture of 0.197 mol carbon dioxide and 0.00278 mol water vapor is held at 30.0 C and 2.50 atm. What is the partial pressure of each gas?
The partial pressure of each gas is the product of its mole fraction and total pressure. The partial pressure of carbon dioxide is 2.46 atm and the partial pressure of water vapor is 0.034.
What is Dalton's law of partial pressures ?Dalton's law of partial pressure states that the partial pressure of the component gases in a mixture is the product of its mole fraction and the total pressure.
Given that, number of moles of carbon dioxide = 0.197 moles.
number of moles of water vapor =0.00278 mole.
mole fraction of carbon dioxide = 0.197 / (0.197 + 0.00278) = 0.98
Total pressure = 2.50 atm
then partial pressure of carbon dioxide = 0.98 × 2.50 = 2.46 atm
Mole fraction of water vapor = 0.00278 / (0.197 + 0.00278) = 0.0139
partial pressure of water vapor = 0.0139 × 2.50 = 0.034 atm.
Therefore, the partial pressure of carbon dioxide and water vapor are 2.46 and 0.034 atm respectively.
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In completing a Fischer Esterification experiment using acetic acid and unknown alcohol catalyzed by sulfuric acid a student starts with excess acetic acid with the intention of shifting the equilibrium towards formation of product. Identify the law used to predict this effect.
Answer:
The equilibrium law
Explanation:
According to the equilibrium law , when [tex]$\text{concentration}$[/tex] of any of the reactants or the products in the reaction at an equilibrium state, is changed, then it changes the composition of equilibrium mixture in order to minimize the effect of
Acetic acid (in excess) + [tex]$\text{alcohol}$[/tex] ⇄ [tex]$\text{ester}$[/tex] + water
[tex]$\text{Fischer esterification}$[/tex] is a reaction which involves the equilibrium. So to force the reaction towards the side of [tex]$\text{ester}$[/tex], one of the reactant is taken in excess. All this can be explained easily by applying the equilibrium law.
How much heat will be absorbed by a 26.3 g piece of aluminum (specific heat = 0.930 J/g･°C) as it changes temperature from 23.0°C to 67.0°C?
Answer:
[tex]\boxed {\boxed {\sf 1076.196 \ Joules}}[/tex]
Explanation:
Since we are given the mass, specific heat, and temperature, we should use the following formula for heat energy.
[tex]q=mc\Delta T[/tex]
The mass of the aluminum is 26.3 grams. Its specific heat is 0.930 Joules per gram degree Celsius. We need to find the change in temperature.
The change in temperature is the difference between the initial temperature to the final temperature. The temperature changes from 23.0°C to 67.0°C, so the initial is 23 degrees and the final is 67 degrees. ΔT= final temperature - initial temperature ΔT= 67°C - 23°C ΔT= 44°CNow we know all the values.
m= 26.3 g c= 0.930 J/g °C ΔT= 44°CSubstitute the values into the formula.
[tex]q= (26.3 \ g}) \times (0.930 \ J/g \textdegree C) \times (44 \textdegree C)[/tex]
Multiply the first two numbers together. The units of grams cancel.
[tex]q= 24.459 \ J/ \textdegree C \times 44 \textdegree C[/tex]
Multiply again. This time, the units of degrees Celsius cancel.
[tex]q=1076.196 \ J[/tex]
1076.196 Joules of heat will be absorbed by the piece of aluminum.
explain the importance of fingerprint record in criminal investigation.
Answer:
One of the most important uses for fingerprints is to help investigators link one crime scene to another involving the same person. Fingerprint identification also helps investigators to track a criminal's record, their previous arrests and convictions, to aid in sentencing, probation, parole and pardoning decisions.
Explanation:
What is the scientific method?
O A. A book describing scientific experiments
B. A description of proper laboratory techniques
O C. A scientific approach to answering questions
D. A way of thinking about scientific problems
Answer:
C.A scientific approach to answering questions
Explanation:
1. Molecules are held together by:
a, ionic bonds
b. covalent bonds
c. both a and b
A: ionic bond, you know why becasue it is
Convert 360 k to Celsius
Answer:
86.85°C
Explanation:
K = °C + 273.15
360K − 273.15 = 86.85°C ≈ 87°C
how much 0.100 m h2so4 are needed to make 25.0 ml of 0.00500 m solution
Answer:
3) 1.25
Explanation:
I had the same question and somehow got it right :)
The new volume will be determined by molarity and which will be 1.25 ml.
What is volume?The volume of an object is just a measurement of how much space it takes up.
What is Molarity?
The molality refers to the moles of a solute in relation to the mass of the solvent, whereas the molarity refers to the moles of a solute in based on the volume of the solution. It can be denoted by M.
The formula of Molarity is
[tex]M_{1} V_{1} =M_{2}V_{2}[/tex]
where, M is molarity and V is volume.
Calculation of volume.
It is given that,[tex]M_{1} = 0.1 M, M_{2} =0.0025 M.[/tex]
Now, puts the value of given data in molarity equation.
[tex]M_{1} V_{1} = M_{2} V_{2}[/tex]
[tex]V_{1} = M_{2} V_{2} /M_{1}[/tex]
[tex]V_{1}[/tex] = 0.005×25/0.1 = 1.25 ml
Therefore, the correct answer will be option 3.
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