Answer:
4 moles
Explanation:
Oxygen gas is O2 (two atoms of oxygen)
2 H2 + O2 = 2 H2 O
one mole of oxygen gas produces TWO moles of water
so you need 4 moles of O2 to produce 8 moles of water
7. Complete the following equations. [2]
a. Sodium + Water ______________________ + Hydrogen
b. Copper carbonate + Sulfuric acid _____________________ +_____________ + Carbon dioxide
c. Sulfur + _________________ Sulfur dioxide
Answer:
Sodium + water --› Sodium hydroxide + hydrogen gas
Copper carbonate + sulphuric acid --› Copper sulphate + water + carbondioxide
Sulphur + Oxygen --› Sulphur dioxide
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Scientists who study objects in space (astronomers) often scan the sky using devices called radio telescopes. What can you conclude about these devices?
Question 10 options:
They send radio broadcasts out to distant stars and planets.
They pick up the radio waves emitted by stars, galaxies, and other objects in space..
They are less powerful than optical telescopes (telescopes that use visible light).
They can detect unltraviolet radiation
If you want to produce 18.48 grams of NaCl what is the minimum amount of each reactant that you must start with
The minimum amount of NaOH and HCl that must be present to produce 18.48grams of NaCl is 12.6g and 11.5g respectively.
Calculation of amount of reactantsThe balanced neutralization reaction equation for the formation of NaCl is,
NaOH + HCl ---> NaCl + H2
The molar mass of NaOH = 23+16+1 = 40g/mol
The molar mass of NaCl = 23 +35.5 = 58.5g/mol
If 40g of NaOH = 58.5g of NaCl
∴ x g of NaOH = 18.48g of NaCl
Make xg the subject of formula,
x g of NaOH = 40 × 18.48/58.5
= 739.2/58.5
= 12.6g of NaOH
The molar mass of HCl = 1 +35.5 = 36.5g/mol
If 36.5g of HCl= 58.5g of NaCl
∴ x g of HCl = 18.48g of NaCl
Make xg the subject of formula,
x g of HCl = 36.5 × 18.48/58.5
= 674.52/58.5
= 11.5g of HCl
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If 25.0 g of NO are produced how many liters,at STP,of nitrogen gas are used?
Answer:
9 1/3 liters
Explanation:
N2 + O2 = 2 NO
Find mole weights from table of elements
N =14
O =~16 30 gm is a mole
22.4 l / mole for gases at STP
22.4 * 25/30 = 18 2/3 Liters of NO
but since Nitrogen is N2 it will take 1/2 s much = 9 1/3
*** EDITED ***
According to the stoichiometry and STP conditions if 25.0 g of NO are produced 2269 liters of nitrogen gas are used.
What is stoichiometry?It 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.1 mole of nitrogen gives 2 moles of NO, thus as per ideal gas equation which on substitution gives V=1×8.314×273/1=2269.722 liters.
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A 300 L sample of hydrogen was compressed to a volume of 200 L at STP. If the initial temperature is 35.0 °C,
what was the initial pressure?
* please show equation!!
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Answer:
76.210kPa
Explanation:
[tex] \frac{p1v1}{t1} = \frac{p2v2}{t2} \\ p1 = \frac{p2v2t1}{v1t1} \\ p1 = \frac{101.325 \times 200 \times 308}{300 \times 273} \\ p1 = 76.210kpa[/tex]
What is the density of a substance with a mass of 20.0 g and a volume of 4.0 mL?
Answer:
20÷4=5g/ml, bcz it is in mL but in other situations you will need to convert it to L by dividing it by 1000
Mass= 20.0g
Volume= 4.0mL
To Find,Density of substance
We Know,[tex]\text{Density} = \frac {\text{Mass}}{ \text{Volume}}[/tex]
Inserting The Values[tex] \text{Density} = \frac{20.0 \text{ \: g}}{4.0 \: \text{mL}} \\ \\ \text{Density} = \frac{ \cancel{20.0}\text{ \: g}}{ \cancel{4.0} \: \text{mL}} \\ \\ \text{Density} = 5.0 \: \text{g/mL}[/tex]
[tex]\therefore \text{Option B}= 5.0 \: \text{g/mL is the correct answer}[/tex]
Hope this helpsCan animals detect radio waves
Answer:
No.
Explanation:
No organism can detect X-rays or radio waves
Answer:
no
Explanation:
Many animals, including vampire bats and certain fish and snake species, are able to sense infrared radiation, but this only goes up to wavelengths of 1mm. Longer wavelengths carry much less energy and can't be detected without some kind of resonator to amplify the signal.
SOMEONE HELP! 100 points have only 2 minutes!
How will different pH levels provide more information?
The neutral phase of a ph scale is 7.
A ph higher than 7 indicates that the substance is basic in nature.
14 is the most basic and 8 is the least basic
A ph lower than 7 indicates the substance is acidic in nature.
1 is the most acidic and 6 is the least acidic.
Who is credited with arranging the periodic table?.
Russian chemist Dmitri Mendeleev
Can someone pls tell me the answer to these 2 fill in the blanks I will surely mark him as the brain list answer
What do the following organic chemicals have in common glyphosphate, lindane, 2,4-d, chlordane
Glyphosphate, lindane, 2,4-d, chlordane are organic compound that have chlorine in common.
What is Organic compound?Organic compound are group of chemical substance that have carbon and hydrogen atoms in which the bonds are covalently linked together.
Therefore, Glyphosphate, lindane, 2,4-d, chlordane are organic compound that have chlorine in common and these chemicals are use as herbicides that is kill weeds, or to kill insects or pests because of chlorine present in it.
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The changes in the mass of the egg and volume of liquid in the beaker are inversely proportional. This demonstrates that _______ is moving from one area to another.
The changes in the mass of the egg and volume of liquid in the beaker are inversely proportional. This demonstrates that volume is moving from one area to another.
What is osmosis?Osmosis is a process in which solvent molecules will move from the higher concentration area to the lower concentration area.
When we put egg in any vessel where water is present then water molecule will move into the egg molecule as a result of the osmosis and due to this mass is inversely proportional to the volume. In this phenomenon water is moving from one area to another due to osmosis.
Hence volume is moving from one area to another.
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Which substances are contained in saliva and tears to break down pathogens?
enzymes
acids
oils
sweat
Answer:
A. Enzymes
Explanation:
Enzymes are in our saliva and tears. They help break down pathogens and the cell wall of bacteria.
I hope it helps! Have a great day!
Muffin~
Answer:
A. Enzymes.
Explanation:
Enzymes break down things and they are in both our saliva and tears.
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.-.
Draw the major product of the given reaction. Include minimized formal charges.
The major product of the given chemical reaction is given as drawn in the attached picture.
What is a Major Product in Chemistry?A major product in chemistry refers to the product whose amount is the greatest after a chemical reaction has taken place.
In order to find the major product, it is required for the Markovnikov Rule to be applied.
This rule states that when hydrogen is mixed with carbon with more hydrogen, then the major product will be gotten.
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Draw a structural formula for the more stable carbocation intermediate formed in the reaction shown.
A carbocation is a carbon atom that bears a positive charge. The most stable carbocation here must be a secondary carbocation .
What is a carbocation?A carbocation is a carbon atom that bears a positive charge. These species pften pccur as intermediates in a chemical reaction and can be detercted spectroscopically.
The most stable carbocation here must be a secondary carbocation hence, the structural formula for the more stable carbocation intermediate formed in the reaction is shown in the image attached.
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40 points please help me very easy!
Answer:
it is charles's law
Explanation:
volume does matter with pressure
pls help me to answer this:(
Answer:
How do one confess feelings to her if he is introvert?
Consider the balanced equation below.
2H2S + 3O2 Right arrow. 2SO2 + 2H2O
Which option gives the correct mole ratios?
H2S:SO2 = 2:2 and O2:H2O = 3:2
H2S:SO2 = 2:3 and O2:H2O = 3:2
H2S:SO2 = 4:4 and O2:H2O = 5:4
H2S:SO2 = 4:6 and O2:H2O = 4:4
Answer:
4:6 and 4:4
Explanation:
double the right side so double the left side to get these ratios
As the pressure on a given sample of a gas increases at constant temperature, the mass of the sample.
Based on the electron configuration of the two atoms, predict the ratio of metal cationic (+) atom to nonmetal anionic (-) atom in the compound.
magnesium 1s22s22p63s2
bromine 1s22s22p63s23p64s23d104p5
a. 1:1
b. 1:2
c. 2:1
d. 3:1
The ratio of metal cationic (+) atom to nonmetal anionic (-) atom in the compound is 1:2.
What is electron configuration?The term electron configuration shows the arrangement of electrons in an atom. We have the configurations of the atoms as follows;
magnesium - 1s22s22p63s2
bromine - 1s22s22p63s23p64s23d104p5
We can see that the catio is Mg^2+ and the anioin is Br^- hence the ratio of metal cationic (+) atom to nonmetal anionic (-) atom in the compound is 1:2.
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Molecules are chemically bonded atoms that work as a unit. Should the same kind of molecule be made up of the same kind of elements? Explain your answer
Answer:
Are molecules atoms that are chemically bonded together?
Image result for Molecules are chemically bonded atoms that work as a unit. Should the same kind of molecule be made up of the same kind of elements? Explain your answer
If this interaction is such that the total energy of the system is lowered, then the atoms bond together to form a molecule. Thus, from a structural point of view, a molecule consists of an aggregation of atoms held together by valence forces. Diatomic molecules contain two atoms that are chemically bonded.
Explanation:
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A sample of an ideal gas has a volume of 2.22 L at 284 K and 1.11 atm. Calculate the pressure when the volume is 1.95 L and the temperature is 305 K.
Answer: 1.36 atm
Explanation:
Write down the word equation for the production of the following salts. Remember to include ALL reactants and ALL products.
2.1 Lithium nitrate, using Lithium carbonate.
2.2 Magnesium chloride using magnesium metal
Answer:
The reaction between methane and oxygen to yield carbon dioxide and water (shown at bottom) may be represented by a chemical equation using formulas (top).
Explanation:
The substances undergoing reaction are called reactants, and their formulas are placed on the left side of the equation.
The substances generated by the reaction are called products, and their formulas are placed on the right sight of the equation.
Plus signs (+) separate individual reactant and product formulas, and an arrow (⟶) separates the reactant and product (left and right) sides of the equation.
The relative numbers of reactant and product species are represented by coefficients (numbers placed immediately to the left of each formula). A coefficient of 1 is typically omitted.
Which substance have the same number of carbon (C) atoms?
Answer:
Carbon monoxide
Explanation:
Carbon dioxide and carbon monoxide have the same number of carbon atoms.
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A dock worker uses a pulley system to raise a boat onto a dock. the pulley system has a mechanical efficiency of 73 %. the boat has a weight of 950 n. the pulley system lifts the boat 5 m into the air. how many newton-metres of work does the dock worker have to exert to lift the boat?
The work (newton-metres) the dock worker have to exert to lift the boat to 5 m in air is 6506.85 Nm
What is work done?This is simply defined as the product of force and distance moved in the direction of the force. Mathematically, it can be expressed as
Workdone (Wd) = force (F) × distance (d)
Wd = Fd
How to determine the output work done Force (F) = 950 NDistance (d) = 5 mOutput work =?Output work = Fd
Output work = 950 × 5
Output work = 4750 Nm
How to determine the input work done Output work = 4750 NmEfficiency = 73%Input work =?Efficiency = (output / input) × 100
73% = 4750 / input
0.73 = 4750 / input
Cross multiply
0.73 × input = 4750
Divide both side by 0.73
Input work = 4750 / 0.73
Input work = 6506.85 Nm
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1. explain how u would test the presence of oxygen and hydrogen gases
2. explain how u can get the most accurate reading in titration
3. why is scientific method important in chemistry? state your opinion
4. you are given a bucket of ice cubes, a little sugar, a measuring cylinder and a stopwatch.Plan a experiment to determine whetther sugar increases the melting rate of ice
Consider the following balanced equation:
2KCIO3 → 2KCI + 302
How many grams of O2 will be obtained by decomposing
98.1 grams of KClO3?
A. 38.4 grams
B. 17.1 grams
C. 76.8 grams
D. 25.6 grams
What cell structure is best represented by the image?
A.
a permeable exoskeleton
B.
a waterproof nuclear envelope
C.
a non-permeable cell wall
D.
a selectively permeable membrane
A
Explanation:
What cell structure is best represented by the image?
A.
a permeable exoskeleton
B.
a waterproof nuclear envelope
C.
a non-permeable cell wall
D.
a selectively permeable membrane
A sample of iron having a mass of 93.3 g is heated to 65.58 oC and is placed in 75.0 g of water raising the temperature of the water from 16.95 o C to 22.24 o C. Find the specific heat capacity for this iron sample. (Specific Heat of Water (C) = 4.184 J/go C)
Answer:
0.271J/g°C
Explanation:
mass of iron=93.3g
∆°C=65.58
mass of water=75g
C of water=4.184
∆°C=22.4-16.95=5.29°C
mc∆°C of iron = mc∆°C of water
93.3×C×5.29=75×4.184×5.29
C=75×4.185×5.29/93.3×65.58
C=0.271J/g°C
Which statement best describes what happens to the carbon dioxide produced by humans?.