Answer:
To identify a pure liquid substance using the physical properties of solubility, density, and boiling point. The physical properties of a pure substance can be measured without changing the composition of the substance.
Explanation:
What are some examples of a chemical change? (list more than 2 examples)
Cooking any food.
Burning of wood.
Digestion of food.
Acid-base reaction.
Melting gold with other metals makes 10-karat gold. Which term best describes 10-karat gold?
homogeneous mixture
compound
heterogeneous mixture
pure substance
Answer: a
Explanation:
Gold is known to be an element. The term that best describes 10-karat gold is that it is an homogeneous mixture.
Gold as an element of often has an ideal state of purity where there contains nothing but gold atoms.
A heterogeneous mixture is known to be a mixture that cannot be chemically sound everytime. Gold jewelry is known to be a homogeneous mixture as it is always will look good and remain unchanged for a long time.
As good example of homogeneous products, e.g a 1-kilogram 24-karat gold bar has unique properties.
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Butane (C4 H10(g), Delta. Hf = â€"125. 6 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2 , Delta. Hf = â€"393. 5 kJ/mol ) and water (H2 O, Delta. Hf = â€"241. 82 kJ/mol) according to the equation below. 2 upper C subscript 4 upper H subscript 10 (g) plus 13 upper o subscript 2 (g) right arrow 8 upper C upper O subscript 2 (g 0 plus 10 upper H subscript 2 upper O (g). What is the enthalpy of combustion (per mole) of C4H10 (g)? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants. â€"2,657. 5 kJ/mol â€"5315. 0 kJ/mol â€"509. 7 kJ/mol â€"254. 8 kJ/mol.
The enthalpy of this reaction is -5315 KJ/mol.
The equation of the reaction is;
2C4H10(g) + 13O2(g) -----> 8CO2 (g) + 10H2O(g)
We know that the enthalpy of reaction can be obtained from the enthalpy of formation of the reactants and products as follows;
ΔHrxn = ΔHf(products) - ΔHf(reactants)
We have the following information from the question;
ΔHf C4H10 = - 125. 6 kJ/mol
ΔHf CO2 = - 393. 5 kJ/mol
ΔHf H2O = - 241. 82 kJ/mol
ΔHf O2 = 0 KJ/mol
Hence;
[(8 × (- 393. 5 )) + (10 × (- 241. 82))] - [2( - 125. 6))]
= -5315 KJ/mol
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Why can the grasses now grow when they couldn’t earlier?
Grasses can grow where they could not earlier because the soil conditions, water volume, or rate of sunlight have evolved.
Each species of plant requires specific conditions to thrive. These conditions include:
Nutrients from the soil.SunlightSpecific amount of water.This implies that if the conditions for a specific species are not provided in terms of sunlight, radiation, and water, the plant will not grow in that specific zone. In the same way, if the conditions of a zone change and they are not suitable for a plant species the plant will grow even if this was not possible before.
This key idea is the reason why some plants including grasses can now grow in zones where they did not exist before. Some of the factors that have contributed to this are:
Fertilization: This provides soils with necessary nutrients.Climate change: This has affected climate patterns, and therefore it can increase or decrease radiation.Irrigation: This increases the amount of water available for plants.Learn more about grass in: https://brainly.com/question/3671945
Calculate the energy of a proton of light with a frequency of 8.5x1014 Hz.
Answer:
[tex] \huge{5.632 \times {10}^{ - 19} \: J}[/tex]
Explanation:
The energy of the proton can be found by using the formula
E = hfwhere
E is the energy in J
f is the frequency in Hz
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question we have
E = 6.626 × 10-³⁴ × 8.5 × 10¹⁴
We have the final answer as
[tex]5.632 \times {10}^{ - 19} \:J[/tex]
Hope this helps you
What role does each type of chemical play in the firework
Answer: Antimony: Antimony is used to create firework glitter effects. Barium: Barium is used to create green colors in fireworks,
Explanation:
Answer:
Explanation:Antimony: Antimony is used to create firework glitter effects. Barium: Barium is used to create green colors in fireworks,
which of the following is the most dangerous type of radiation?
gamma decay, alpha decay, beta, decay, they are all equally dangerous
Answer:
gamma decay
Explanation:
gamma rays have the highest frequency on the EM spectrum, which makes them the most dangerous.
How do you determine the group and period of an element based on its electron configuration?
Answer:
If you are given with the atomic number of an element you can find it's period number and group number. The period number is related to the number of electron occupied shells in the element and the period number is linked to its valence electrons.
Explanation:
hope it helps luv <3
5 Stoichiometry Chemistry questions !
1. Determine the mass in grams of lithium hydroxide produced when 0.38 g of lithium nitride reacts. g LiOH
Li3N(s) + 3 H2O(l) --> NH3(g) + 3 LiOH(aq)
2. How many moles of sodium chloride are produced when 2.9 grams of sodium iodide reacts? mol NaCl
2 NaI(s) + Cl2(g) --> 2 NaCl(s) + I2(g)
3. What volume in liters of chlorine gas at STP would be required to fully react with 125 g of NaI? L Cl2
2 NaI(s) + Cl2(g) --> 2 NaCl(s) + I2(g)
4. Determine the volume in liters of carbon dioxide produced at STP when 0.85 grams of butane (C4H10) reacts. L CO2
2 C4H10(l) + 13 O2(g) --> 8 CO2(g) + 10 H2O(g)
5. Calculate the mass in grams of water vapor produced by the combustion of 51.3 L of propane, C3H8, at STP. g H2O
C3H8(g) + 5 O2(g) --> 3 CO2(g) + 4 H2O(g)
Most stars are part of the main sequence of stars in the HR diagram
Question 2 options:
True
False
Answer the following questions.
P1) Matching.
Complete the table with the data from the lab. First, calculate and enter the mole ratio in the chart, then enter the volumes of the precipitates.
The mole ratio can be seen below and the volume of each precipitate is 60 mL.
A mole ratio refers to a conversion factor that compares the quantities of two chemicals in moles in a chemical laboratory experiment.
Mole ratio For 1:
= 10 mL : 50 mL= 1 : 5 mLMole ratio For 2:
15 mL : 45 mL= 1 : 3 mLMole ratio For 3:
20 mL : 40 mL1 : 2 mLMole ratio For 4:
30 mL : 30 mL1 mL : 1 mLMole ratio For 5:
40 mL : 20 mL2 : 1 mLMole ratio For 6:
45 mL : 15 mL3 : 1 mLMole ratio For 7:
50 mL : 10 mL5 : 1 mLSince the parameters from the left side of the diagram are not shown, we will assume that the volumes for each precipitate are the addition of both volumes in each column.
By doing so, we have:
1.
(10 +50) mL = 60 mL2.
(15 + 45) mL = 60 mL3.
(20 + 40)mL = 60 mL4.
(30 + 30) mL = 60 mL5.
(40 + 20)mL = 60 mL6.
(45 + 15) mL = 60 mL7.
(50 + 10)mL = 60 mLLearn more about mole ratio here:
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How many molecules does 1 mole of Oz gas have?
awnser : 6.02×1023 molcules
how does one determine a molecular formula from the epirical formula
Answer:
C
Explanation:
Write the shape of s and p-orbials.
s-orbitals are spherical, while p-orbitals are similar to a 3-D infinity symbol. I have attached an image of the comparison.
which particle diagram represents a sample of oxygen gas at stp
The diagram in image (4) in the image attached represents a sample of oxygen gas at stp.
Oxygen is a diatomic molecule, a diatomic molecule is a molecule that consists of only two atoms of the same element. In this case, the oxygen molecule consists of two oxygen atoms.
If we look at the diagram in the image attached very well, we will discover that the image in diagram (4) shows a molecule composed of two atoms of the same element and this fits exactly into the description of the oxygen molecule.
Learn more about diatomic molecules:
Particle diagram 4 represents the particles of oxygen at standard temperature and pressure.
A model of molecular (or diatomic) oxygen, which is made up of two oxygen atoms attached to each other through a covalent bond.
Dioxygen, also known as oxygen, is a naturally occurring molecule made up of two oxygen atoms that attach to each other with a strong covalent bond to form oxygen (dioxygen). Oxygen is sp3-hybridized, i.e. it has 4 sp3 hybrids. One of these hybrid orbitals overlaps with the s orbitals of hydrogen to create the O-h sigma bonds.
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#SPJ6
The diagram in question is attached below.
Which dosage form is a semisolid preparation that contains very small solid particles that are suspended in a liquid
A GEL is a semisolid preparation that contains very small solid particles that are suspended in a liquid. A gel always contains an agent (e.g., agarose) that provides stiffness to the preparation.
A gel is a semisolid preparation that contains a gelling agent which provides stiffness to the preparation.
The gelling agent can be, for example, agarose (this gelling agent is used to prepare gels in electrophoresis).
In an agarose gel, agarose molecules are organized into three-dimensional (3D) structures similar to pores, which allow the passage of DNA fragments during electrophoresis.
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2.Photosynthesis and combustion of coal are two chemical reaction taking place.How can you describe both reactions on the basis of energy transfer?
PLEASE HELP QUICK I NEED 14-16 (JUST 6 PROBLEMS) ANSWERED AND FULL WORK SHOWN FOR FACTOR LABEL METHOD ITS 100 POINTS AND I WILL MARK BRAINLYEST.
Answer:
14. 21.51 liters
15. 12.9 centimeters
16. 3400 milliliters
Explanation:
I don't really know how to show the work
I know the answer is A/1 but I’m not sure how to explain it, I would like some help on the explanation part
3. The accompanying diagram represents a cell in water. Formulas of molecules that can move freely across the cell membrane are shown. Some molecules are located inside the cell and others are in the water outside the cell.
(Picture) diagram
Based on the distribution of these molecules, what would most likely happen after a period of time?
A. The concentration of O₂ will increase inside the cell.
B. The concentration of CO₂ will remain the same inside the cell.
C. The concentration of O₂ will remain the same outside the cell.
D. The concentration of CO₂ will decrease outside the cell.
Answer:
number one is the correct option
In the conclusion to the snake mole lab, you have to convert 3.45 moles of (NH4)2S04 to
grams. What is the molar mass of (NH4)2504?
why do i have white spots on my teeth after brushing?
which acid is part of the white coating on sour patch kids?
Tartaric acid is the white, powdery substance that coats tart candies such as Sour Patch Kids. COmbustion analysis of a 12.01g sample of tartaric aid, which contains carbon, hydrogen and oxygen, produces 14.08g CO2 and 4.32g
H2O.
i would know because i have see what there made of
Fast pls due rn help fast pls
Answer:
Section a:
1. stratosphere
2. radio waves
3. nitrogen, oxygen
4. humidity
5. smoke, fog
Section b:
1. ozone layer
2. stratosphere
3. carbon dioxide (CO2)
4. smoke
5. tropical areas
Section c:
1. false, it is clear
Hope those help and are all correct
Find the molecular formula of ethylene glycol, used in antifreeze, if its empirical formula is CH3O and its molar mass is 62 g/mol.
The molecular formula of the ethylene glycol is C₂H₆O₂.
From the question given above, the following data were obtained:
Empirical formula = CH₃O Molar mass of compound = 62 g/mol Molecular formula =?Molecular formula = empirical × n = molar mass
[CH₃O]n = 62
[12 + (3×1) + 16]n = 62
31n = 62
Divide both side by 31
n = 62 / 31
n = 2
Molecular formula = [CH₃O]n
Molecular formula = [CH₃O]₂
Molecular formula = C₂H₆O₂
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What is a trial? please
 A car has a displacement of 480 km to the east in eight hours. What is its velocity in kilometers per hour?
[tex] \sf = \frac{480}{8} = 60[/tex]
Answer:
The velocity of the car is 60 Km/hour to the east.
Hope you could get an idea from here.
Doubt clarification - use comment section.
When heat is being transferred away from a substance, the resulting phase change graph is known as a ____ curve.
a. Cooling
B. Heating
What type of reaction takes place when using this enzyme (endergonic or exergonic)?
lactase is the enzyme
Answer:
we do the best possible in our
PLEASE help in the middle of a test: When table salt forms, which action occurs between the reacting elements?(1 point)
Answer:
don't know if this is what your looking for but it might be a NEUTRILIZATION REACTION.
Answer:
i think its sodium donates an electron to chlorine
Explanation:
what object has a mass of 10 grams and a volume of 2 mL
Answer:
Destiny = 5 g/ml
Explanation:
The formula for density is d=
Knowing this, divide your mass by volume:
10 g / 2 ml = 5 g/ml
Final answer:
Destiny = 5 g/ml