Answer:
Fossils of the same animals have been found on South America and on Africa.
Africa and South America look as if they could be fit together perfectly (they almost can!)
Explanation:
Basically, the idea is that South Africa and Africa were once the same landmass. The same animals lived in that landmass, but when they broke off, then the animals were on different continent, yet they came from the same place.
Metal X is soft and can be cut with a knife. It reacts vigorously with air and water. Identify metal X-
iron
copper
Sodium
gold
Answer:
The metal is most likely Sodium.
Explanation:
Iron is not soft enough to be cut with a knife and will not react violently with water. When Iron reacts with water it just slowly rusts.
Copper is somewhat malleable, however, does not really react with water and only forms an oxide layer in the air.
Sodium is soft enough to be cut with a knife (I know this because I have worked with it and seen people work with it). It is also an alkali metal which are known to explode when in water.
Gold is malleable but does not really react with anything and is considered inert.
A 0.4505 g sample of a pure soluble bromide compound is dissolved in water, and all of the bromide ion is precipitated as AgBr by the addition of an excess of silver nitrate. The mass of the resulting AgBr is found to be 0.7514 g. What is the mass percentage of bromine in the original compound
Answer:
70.98% is the mass percentage of bromine in the original compound
Explanation:
First, we need to convert mass of AgBr to moles with its molar mass (AgBr: 187.77g/mol). Moles of AgBr = Moles of Br. With molar mass of Br-: 79.904g/mol we can find mass of bromide and mass percentage as follows:
0.7514g AgBr * (1mol / 187.77g) = 0.00400 moles AgBr = Moles of Br-
0.00400 moles Br- * (79.904g / mol) = 0.320g Br- in the sample
Mass percentage is:
0.320g Br- / 0.4505g sample * 100
70.98% is the mass percentage of bromine in the original compoundHelp please! please answer with a good answer
Answer:
what the heck what is that?
Explanation:
IMESSAGE GAMES ANYONE?
Answer:
oop whats dis
Explanation:
1. At room temperature, air is usually a (solid, liquid, gas).
Answering the following questions will help you focus on the outcomes of the experiments. Experiment 1: What happens to the water in the small tube as the water in the test tube absorbs heat? Why do you think a small tube was used to observe the expansion of water? Experiment 2: Compare the circumference of the balloon before and after freezing. What is the percent increase in this measurement? Combined Results Write a summary paragraph discussing this experiment and the results. Use the following questions and topics to help guide the content of your paragraph. Summarize the conclusions that you can draw from this experiment. Use the questions above to guide your ideas. Summarize any difficulties or problems you had in performing the experiment that might have affected the results. Describe how you might change the procedure to avoid these problems. Describe at least two real-world issues or examples that illustrate the findings of this experiment.
Answer:
Use a glass testtube
Insert a 1-hole stopper in which you insert a glass tube (use a bit of glycerine around the bottom end which makes it slip easier into the stopper)
Fill the testtube with colored water
Place rubber stopper
Make sure there are no air bubbles and that the column in the glass tube is low, as indicated
Place testtube assembly into water which you will heat (hot plate)
Observations
You will observe that the water column in the glass tube moves up as the temperature of the water in the testtube increases. With a 20 mL testtube, and a temperature change from 20 degrees C to 80 degrees C, you should get something like 15-20 cm of change in height.
What do YOU observe?
How do YOU explain your observation?
What is happening there?
Explanation
The water in the testtube expands as it is heated. There is only one direction to expand in, the glass tube. This glass tube is narrow so that a small change in volume will result in a considerable change in height; your signal is amplified.
This is the same phenomenon as in thermometers with a glass bulb on the lower end. Thermometers use a variety of liquids including alcohol (expands more than water) and mercury (is dangerous when spilled).
Explanation:
hope this helps
Answer:
Experiment 1:
What happens to the water in the small tube as the water in the test tube absorbs heat?
Answer: As the water in the test tube absorbs heat the water in the small tube continues to rise
Why do you think a small tube was used to observe the expansion of water?
Answer: The small tube was used to observe the expansion of water to show a visible change that could also be measure with a ruler
Experiment 2:
Compare the circumference of the balloon before and after freezing. What is the percent increase in this measurement?
Answer: The circumference of the balloon increased after it was put in the freezer. The measurement increased by about 5%, it started at 39.5cm then increased to 41.5cm
According to the data, an increase in temperature caused the water molecules to expand because it gained energy which caused it to move more rapidly ultimately resulting in an increase of volume of water. In addition, when being froze water expands making it less dense than the water from which it freezes, causing the volume to also increase. The difficulty I faced in this experiment is pinpointing the exact change in the waters expansion. Two real world issues are when icebergs float as a result of water freezing resulting in expansion, another one is the warming of Earth due to the heat-trapping from greenhouse gases. This heat is absorbed by oceans and seas causing the temperature to rise and the water to expand.
Explanation:
Ava threw a hamster at her sister the other day she used 12N of force to accelerate the hamster at 8m/s2.what was the mass of the poor hamster?SHOW ALL WORK
We are given:
The force applied on the poor hamster (F) = 12 N
Acceleration of the poor Hamster (a) = 8 m/s²
Solving for the mass of the Poor Hamster:
From newton's second equation of motion, we know that:
F = ma
replacing the given values
12 = 8 * m
m = 12/8 kg
m = 3/2 kg
The poor Hamster weighs 3/2 kg
How many atoms of hydrogen would need to bond with a single atom of selenium to form a molecular compound?
Answer:
Hydrogen sulfide reacts with aqueous selenous acid to produce selenium disulfide:
H2SeO3 + 2 H2S → SeS2 + 3 H2O
Selenium disulfide consists of 8-membered rings. It has an approximate composition of SeS2, with individual rings varying in composition, such as Se4S4 and Se2S6. Selenium disulfide has been used in shampoo as an antidandruff agent, an inhibitor in polymer chemistry, a glass dye, and a reducing agent in fireworks.[15]
Selenium trioxide may be synthesized by dehydrating selenic acid, H2SeO4, which is itself produced by the oxidation of selenium dioxide with hydrogen peroxide:[17]
SeO2 + H2O2 → H2SeO4
Hot, concentrated selenic acid can react with gold to form gold(III) selenate.[18]
If 8.2 mL of 0.055 M NaOH is required to titrate a 5.5 mL sample of potassium bitartrate, what is the [K +]?
Answer:
.082 M
Explanation:
You just do C1V1=C2V2
The concentration of the potassium bitartrate acid is determined as 0.082 M.
Concentration of the acidThe concentration of the potassium bitartrate acid is calculated as follows;
C1V1 = C2V2
where;
C1 is the concentration of the base = 0.055V1 is the volume of the base = 8.2 mlC2 is the concentration of the acidV2 is the volume of the acid = 5.5 mlC2 = (C1V1)/(V2)
C2 = (0.055 x 8.2)/(5.5)
C2 = 0.082
Learn more about concentration here: https://brainly.com/question/17206790
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Sodium sulfate solution contains sodium lons, Na+, sulfate ions, (SO4)2-, hydrogen ions, H+, and hydroxide ions, OH-.
When sodium sulfate is electrolyzed, hydrogen is produced at one electrode and oxygen is produced at the other electrode.
Explain how these products are formed from the ions in the electrolysis process, indicating how you would identify the products.
(6 marks)
Water is oxidized and reduced at both electrodes
Further explanationElectrolysis utilizes electrical energy to carry out non-spontaneous redox reactions. The ions in the solution flowed by an electric current will move toward the electrode opposite the charge.
The negative ions from the solution will move towards the positive electrode, and release electrons around the positive electrode (oxidation occurs) and electrons flow to the negative pole
While around the negative electrode electron binding occurs and a reduction reaction occurs
the reaction at the cathode:
1. the reduced active metal is water, other than that the metal will be reduced
2. H⁺ of the acid will be reduced
For reactions in anode:
1. if the electrodes are not inert then the metal is oxidized
2. If inert then:
a. OH⁻ from the base will be oxidized
b. The halogen metal will oxidize
Na⁺ (cathode)⇒metal group 1 and 2 ⇒ H₂O reduced2H₂O(l)+2e⁻⇒ H₂(g)+2OH⁻(aq)
SO₄²⁻ (anode)⇒acid ion(oxyacid)⇒H₂O oxidized2H₂O(l)⇒4H⁺(aq)+O₂(g)+4e⁻
Which of the following is an example of a physical change?
А.
sugar and oxygen reacting to produce water and carbon dioxide
B
honey dissolving in tea
С
a raw egg being cooked
D
metal rusting after being left out in the rain
Answer:
B. honey dissolving in tea
Explanation:
Lexi is balancing equations. She is finding one equation to be very difficult to balance. Which explains how to balance the equation ZnSO4 + Li2CO3 → ZnCO3 + Li2SO4?
Answer:
deez
Explanation:
thx
Answer:
Atoms in the equation are already in balance
Explanation:
It's D
The reference point in motion is:
A. The point in space and time at which the motion ended
B. The point in space and time at which the motion began
C. The focal point
D. The origin
Answer: the focal point
13. As heat is added to a lúguid that is boiling at constant
pressure, the temperature of the liquid
A) decreases B) increases
C) remains the same
A
B
Question 2
The higher the energy, the higher or lower the wavelength? This is an example of a/an direct or inverse relationship?
Answer:
the higher the energy tje lower the wavelength
Explanation:
inverse relationship
Answer:
It's an example of an inverse relationship :)
A covalent bond is formed by:
loss of electrons between atoms
sharing of electrons between atoms
gain of electrons between atoms
valence electron shells overlaping, forming a "sea of electrons"
Answer:
sharing of electrons between atoms
How much energy, in kilojoules, must you add to 3.00 quarts of olive oil to warm it from 23.0 °C to 100.0 °C? The specific heat of olive oil is 0.1.79 J/g·°C and its density is 0.916 g/mL
Answer:
3.58*10^-4kJ
Explanation:
Given
T1=23.0 °C
T2=100.0 °C
c=1.79 J/g·°C
Volume of olive =3 quarts
Converting to liter
1 quart =0.946353 L
3 quarts=x
Cross multiplying
x=0.946353*3
x=2.83L
To mL= 0.0028mL
We are given the density as 0.916 g/mL
Mass= density *volume
Mass= 0.916*0.0028
Mass=0.0026g
We know that the quantity of heat is expressed as
Q=mcΔT
Q=0.0026*1.79(23-100)
Q=0.004654*(77)
Q=0.358J
In kJ we divide 0.36 by 1000
=0.000358358
=3.58*10^-4kJ
What is percent error calculation used to determine
Acetylene gas (C2H2) is used in welding torches. When it reacts with oxygen, it produces
carbon dioxide (CO2) and steam (H20). The reaction can be described by the equation 2C2H2+
502 —> 4CO2 + 2H20. How much mass of C2H2 is needed to produce 75.0 grams of CO2?
Mass C₂H₂ needed : 22.165 g
Further explanationReaction
2C₂H₂+ 5O₂ ⇒ 4CO₂ + 2H₂O
75.0 grams of CO₂ , mol CO₂ (MW=44 g/mol) :
[tex]\tt \dfrac{75}{44}=1.705[/tex]
mol C₂H₂ :
[tex]\tt \dfrac{2}{4}\times 1.705=0.8525[/tex]
mass C₂H₂ (MW=26 g/mol) :
[tex]\tt 0.8525\times 26=22.165~g[/tex]
If 17.8 g grams of lithium (Li) are combined with 50.0 grams of water (H20) there is
24.7 grams of hydrogen gas (H2) produced. How much lithium hydroxide (LiOH) was
also produced?
Answer:
Explanation:
Li+H2O..................LiOH+H2
mass of Li=17.8 g
No of moles of Li=17.8/7=2.5
mass of H2O=50.0 g
No of moles of H2O=50.0/18=2.8
limiting reagent is Li so 1 mole of Li produce 1 mole of LiOH therefore 2.5 mole of Li produce 2.5 moles of LiOH now we have to convert it into grams
moles=given mass/molar mass
given mass=moles*molar mass
molar mass of LiOH=24
mass=2.5*24=60 gram
If a liquid is said to have high viscosity it is...
Answer:
Viscosity is the measure of resistance of a fluid to flow. A fluid that is highly viscous has a high resistance (like having more friction) and flows slower than a low-viscosity fluid. To think of viscosity in everyday terms, the easier a fluid moves, the lower the viscosity
Explanation:
How many grams of KOH are required to prepare 500. mL of 0.450 KOH solution?
Answer:
KOH molar mass = 39 + 16 + 1 = 56g
To make 1 L of 1M soln needs 56g KOH
To make 500mL 1M needs 56/2 = 28g
To make 500mL 0.2M needs 28 x 0.2gn:
When elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it. true or false
Answer:
True
Explanation:
Why do you think some things float and some things sink?
Answer:
because some things have a higher density than other things
Explanation:
Answer:
some things float bc they have air inside of them which makes them rise bc air rises and gravity pulls so theyre working against each other. some things sink bc theyre heavy and gravity is already pulling them down so them being heavy just makes them sink faster. hope this helps!!!
Explanation:
Convert from 1.56×1030 particles of sodium chloride (NaCl) to grams of sodium chloride.
Answer:
15.14×10⁷ g
Explanation:
Given data:
Number of particles of NaCl = 1.56×10³⁰ particles
Mass of sodium chloride = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ particles
1.56×10³⁰ particles × 1 mol / 6.022 × 10²³ particles
0.259 ×10⁷ mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 0.259 ×10⁷ mol × 58.44 g/mol
Mass = 15.14×10⁷ g
- Which particles are found in the nucleus of an argon
atom?
Answer:proton,neutrons,and electrons.
Explanation:
Question 1 Give the correct number of significant figures for 4500, 4500., 0.0032, 0.04050
Question 2 Give the answer to the correct number of significant figures:
4503 + 34.90 + 550 = ?
the correct number of significant figures.
uction 2 Give
Answer:
Question 2
5087.9 or 5088
What is the Molarity of 25 g of C6H12O6 in 25 mL of H2O?
Answer:
5.6 M
Explanation:
Given data:
Mass of C₆H₁₂O₆ = 25 g
Volume of solution = 25 mL (25 mL×1 L/1000 mL=0.025 L)
Molarity of solution = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of C₆H₁₂O₆:
Number of moles = mass/molar mass
Number of moles = 25 g/ 180.16 g/mol
Number of moles = 0.14 mol
Molarity:
M = number of moles / volume in L
M = 0.14 mol/ 0.025 L
M = 5.6 M
Name the two ways by which
suspended impurities present
in water can be removed
Answer:
Common water treatment processes such as flocculation, sedimentation, filtration and disinfection are employed to remove general impurities such as floating and suspended matters, colloidal particles, dissolved organic matter and destruction of disease-causing microorganisms (pathogens).
Explanation:
One mole of an ideal gas expands reversibly and isothermally from 10. bar to 1.0 bar at 298.15K.
Required:
a. Calculate the values of w, q, âU and âH?
b. Calculate w if the gas were to have expanded to the same final state against a constant pressure of 1 bar.
Answer:
a. W = 5,708 J, Q = 5,708 J, ΔU = 0 and ΔH = 0.
b. 2,231 J.
Explanation:
Hello!
a. In this case, since this is an isothermal process (constant temperature) it is possible to infer that the work is computed as shown below:
[tex]W=nRTln(\frac{p_1}{p_2} )=1mol*8.314\frac{J}{mol*K}*298.15Kln(\frac{10.bar}{1.0bar} )\\\\W=5708J[/tex]
Now, since this is an isothermal process we know by definition ΔU = 0 and ΔH = 0, therefore the involved heat is:
[tex]Q-W=0\\\\Q=W=5708J[/tex]
b. In this case, since the process is isobaric but goes to the same final volume in part a, we can compute the initial and final volume based on the part a's conditions by using the ideal gas equation:
[tex]V_1=\frac{nRT}{p_1} =\frac{1mol*0.083145\frac{*L}{mol*K}*298.15K}{10.bar} =2.48L\\\\V_2=\frac{nRT}{p_2} =\frac{1mol*0.083145\frac{*L}{mol*K}*298.15K}{1.bar} =24.8L[/tex]
Thus, the work done here is:
[tex]W=p(V_2-V_1)=1bar(24.8L-2.48L)=22.3bar*L*\frac{1x10^5Pa}{1bar} *\frac{1m^3}{1000L} \\\\W=2231J[/tex]
Best regards!