which sample is a pure substance?
a. a test tube of zinc oxide
b. a container of zinc and oxygen
c. a flask of pond water
d. a jar of soil
Answer:
The answer is A. Test Tube of zinc oxide
you need 16.66ml (+-0.01) of 53.4 (+-0.4)wt% of NaOH with a density of 1.52 (+-0.01)g/mL to prepare 2.00L of 0.169M of NaOH. What is the uncertainty in the molarity of NaOH. FM of NaOH=39.9971 g/mol. Neglect the uncertainty in the final volume and FM.
Answer:
The absolute uncertainty is approximately 1.69 × 10⁻³
Explanation:
The volume needed for NaOH needed to make the solution = 16.66 ml
The wt% of the added NaOH = 53.4 wt%
The volume of the NaOH to be prepared = 2.00 L
The concentration of the NaOH to be prepared = 0.169 M
The molar mass of NaOH = 39.997 g/mol
Therefore, 100 g of sample contains 53.4 g of NaOH
The mass of the sample = 16.66 × 1.52 = 25.3232 g
The mass of NaOH in the sample = 0.534 × 25.3232 = 13.5225888 g ≈ 13.52 g
Therefore;
The number of moles of NaOH = 13.52/39.9971 = 0.3381 moles
Therefore, we have 0.3381 moles in 2.00L solution, which gives;
The number of moles per liter = 0.3881/2 = 0.169045 moles/liter
The molarity ≈ 0.169 M
The absolute uncertainty, u(c) is given as follows;
[tex]u(c) = \sqrt{ \left (\dfrac{0.01}{16.66} \right )^2 + \left ( \dfrac{0.4}{53.4} \right )^2 + \left ( \dfrac{0.01}{1.52} \right )^2 } \times 0.169 \approx 1.69 \times 10^{-3}[/tex]
The absolute uncertainty, u(c) ≈ 1.69 × 10⁻³.
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Does temperature have the same effect on gases as it does on liquids when it comes to viscosity? Explain.
When the temperature of a liquid (fluid) decreases, its viscosity increases. What happens to this fluid?
As the temperature of a liquid (fluid) increases, its viscosity decreases. What happens to this fluid?
Why does ketchup flow faster when heated?
Answer: Explanation:
With an increase in temperature, there is typically an increase in the molecular interchange as molecules move faster in higher temperatures. The gas viscosity will increase with temperature. ... With high temperatures, viscosity increases in gases and decreases in liquids, the drag force will do the same.
The increase in temperature causes the kinetic or thermal energy to increase and the molecules become more mobile. The attractive binding energy is reduced and therefore the viscosity is reduced.
liquids show a reduction in viscosity with increasing temperature. With high temperatures, viscosity increases in gases and decreases in liquids, the drag force will do the same.
What is the pi of 80,000 and 400000
Answer:
london I'm not dead -yet-
Explanation:
thank u for being there for me when no one else was
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the number of protons will tell you what elements it is. T or F plzz help
Answer:
True
Explanation:
There are two ways to tell elements apart from each other: the atomic number or the number of protons. The atomic number tells the number of protons in the element.
For example:
There are two given elements. One has 3 protons and an atomic number of 3 while the other has 7 protons and an atomic number of 7. Which one is Lithium?
Lithium has an atomic number of 3, which means it has three protons, which means Lithium is the one with 3 protons.
describe what you think will happen to a balloon that has been fully inflated and Port into a hot place explain your prediction
Answer:
Explanation:
A balloon if fully inflated and then placed close to a hot place is likely to blow. This would result from the increased air pressure inside the balloon. Increase in temperature leads to an increase in the energy of the air molecules which move at a higher speed and more collisions.May 11, 2018
What are the different parts of a comet?
Answer:
the nucleus, the coma, the ion tail, and the dust tail
Explanation:
A comet is made up of four visible parts: the nucleus, the coma, the ion tail, and the dust tail. The nucleus is a solid body typically a few kilometres in diameter and made up of a mixture of volatile ices (predominantly water ice) and silicate and organic dust particles.
A force is always a push. true or false ?
PLS HELP!! ASAP!! 10 POINTS!!
From Dalton's atomic theory, a few parts were disproven over the course of years of experiments. Which part was modified by the discovery of subatomic particles?
That matter is made of atoms.
If the same elements are in a two different compounds, their ratio will always be the smallest whole number ratio for that compound.
That atoms cannot be divided.
That all atoms of an element are exactly the same
The indivisibility of an atom was proved wrong: an atom can be further subdivided into protons, neutrons and electrons. ... According to Dalton, the atoms of same element are similar in all respects. However, atoms of some elements vary in their masses and densities. These atoms of different masses are called isotopes.
What are the physical properties of gases, and how do they change under certain conditions?
Answer: Gases expand to fill their containers, have a fluid nature, low density, can be compressed, diffuse and effuse - move in small hole spray perfume .
Explanation:
Gases have such an unpredictable nature like fluid, very low density, can be condensed, disperse and effuse move in tiny hole spray fragrance, and they dominate far more room than the fine solids out of which they establish.
Because gases are harder to identify directly, gases are defined using four physical qualities or observable characteristics such as temperature, density, particles number, and volatility.
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Annalise observes a streak of light in the sky and says she is seeing a shooting star. What is she most likely observing?
a falling star
an asteroid
a meteor
a dwarf planet
Answer: A Meteor
Explanation:
A streak of light in the sky and says she is seeing a shooting star. She's most likely observing is a meteor. Therefore, option C is correct.
What is a meteor ?A meteor is an object from space or a meteoroid that touches down on Earth. The air on the space rock creates drag that causes it to become incredibly heated as it falls toward Earth.
When the earth travels through cometary debris during its orbit around the Sun, meteor showers will result. Although the Earth's orbit around the Sun is nearly round, the majority of comets have very elliptical orbits.
A meteoroid becomes a meteor, or a streak of light in the sky, if it gets close enough to Earth and enters its atmosphere. These light striations are sometimes referred to as "shooting stars" due to their appearance. However, stars are not what meteors are.
Thus, option C is correct.
To learn more about meteor, follow the link;
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The mass of an object is 24g and the volume of the object is 16 mL. Calculate the
density of the object?
Answer:
D = m/v
Explanation:
So m = 24g and v = 16mL. (I assume these are the units being used). Then, we get D = 24g/16mL which is 1.5 g/mL
Is wax ionic or covalent? why?
Answer:
Candle wax will melt to a liquid and burn as a gas. Only covalent compounds can be liquid or gas!
Explanation:
Question: Is Wax Ionic Or Covalent? - Ceramicsexpandusceramics.com
In the given question, wax is a covalent compound because it is composed of nonmetal atoms that share electrons to create covalent bonds.
Covalent compounds are formed when two or more nonmetal atoms share electrons in order to achieve a stable electron configuration.
Wax is made up of long-chain hydrocarbons, which are molecules that contain only carbon and hydrogen atoms. The carbon and hydrogen atoms in these molecules share electrons to form covalent bonds.Ionic compounds, on the other hand, are formed when a metal and a nonmetal react.Therefore, wax is a covalent compound because it is made up of non-metal atoms sharing electrons to form covalent bonds.
Learn more about covalent compounds here:
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The equation, reactants
product + thermal energy, describes a(n)_____
reaction.
Answer: Here you go
Explanation:
The general equation for an exothermic reaction is: Reactants → Products + Energy.
determine the density of a liquid if 75 mL of the liquid have a mass of 63 g
Answer:
The answer is 0.84 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 63 g
volume = 75 mL
We have
[tex]density = \frac{63}{75} = \frac{21}{25} \\ [/tex]
We have the final answer as
0.84 g/mLHope this helps you
A substance has an atomic number of 80 and a mass number of 178. How many protons does this atom have? How many neutrons does it have? How did you determine this? Write your answer in ACES format.
Answer:
Cite (source and evidence):
Explain:
Summarize:
Answer:
This atom has 80 protons and 98 neutrons.
Explanation:
All atoms are composed of a central nucleus in which there are positively charged particles, the protons, and neutrally charged particles, the neutrons, around which other negatively charged particles, called electrons, move.
The atomic number, identified with the letter Z, indicates the number of protons that are present in the nucleus of an atom. The atomic number defines the electronic configuration of the atom and allows the ordering of the different chemical elements in the periodic table.
If a substance has an atomic number of 80, this atom has 80 protons.
The mass number indicates the total number of particles in the nucleus, that is, the sum of protons and neutrons.
mass number = number of protons + number of neutrons
In this case you know that the mass number is 178 and number of protons is 80. Then
number of neutrons=mass number - number of protons
number of neutrons= 98
So this atom has 98 neutrons.
Describe how the particle motion is different from state to state.
Answer:
The particles in a gas are moving very quickly in random directions.
The particles in a solid are tightly packed and locked in place, and they are vibrating in their place.
The particles in a liquid are close together (touching) but they are able to move/slide/flow past each other.
brainliet please?
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Which example best demonstrates stewardship of the atmosphere
Incomplete question. However, I provided a specific example of stewardship of the atmosphere.
Explanation:
First, note that the term stewardship refers to the belief that humans are obligated to take care and look after our environment (which includes the atmosphere.
An example of this is: deciding to change our mode of transportation: What this entails is that we may decide to switch to riding a bicycle to places rather than going by car. By so doing you will be reducing the number of greenhouse gases emitted into the environment as bicycles do not emit harmful gases when used.
How many elements make up Sodium Bicarbonate?
PLEASE HELP ME!!
Water (H2O) is composed of the same elements as hydrogen peroxide (H2O2).
Why do these substances have different properties?
The molecules are the same.
Water has more atoms than hydrogen peroxide.
The atoms are arranged differently in each molecule.
The atoms are the same.
Answer:
The molecules are the same.
Explanation:
This element has 2 fewer protons than Titanium. What element is it?
Answer:
calcium.
Explanation:
because of
thanks
How long does it take for the water to start boiling? At what temperature does the water boil?
Answer:
At sea level, or at zero feet in altitude, the boiling point of water is at 212 °F (100 °C). Once the water has reached this boiling point, the US Center for Disease Control recommends keeping it at a rolling boil for about a minute to make sure it is purified.
Answer:
Water boils at 212 degrees fahrenheit or 100 degree celcius
Explanation:
its true
Quartzite is a coarse-grained rock derived from sandstone.
Which type of rock is quartzite?
metamorphic
extrusive
sedimentary
igneous
Answer:
granoblastic metamorphic rock
Explanation:
Calculate number of moles in 42g of silicon.
Answer:
[tex]\frac{3}{2}[/tex]
Explanation:
No of moles : [tex]\frac{given mass}{atomic mass}[/tex]
so the given mass is 42 gm and atomic mass of silicon is 24 when u solve it u get 3/2
What happens to particles in a sample of liquid when the liquid is heated and cooled?
What does the speed of the mixing colors tell you about the speed of the
molecules in hot and cold water?
When bonding, what is most likely to happen between the atoms listed below?
A.) Atom X will donate electrons to Atom Y
B.) Atom X will accept electrons from Atom Y
C.) Atom Y will accept electrons from Atom Z
D.) Atom Z will donate electrons to Atom X
Answer:
atom x will accept electrons from atom y
Explanation:
in bonding the main purpose is to gain stable electronic configuration hence atom y will give out the two valence electrons to atom x
this kind of bonding where one of the atom is the one donating the electrons is known as ionic bond.
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Answer: YEAH ITS the third one
Explanation: duhh
What mass of the calcium carbonate, to the nearest hundredth of a gram, is decomposed in this reaction.
Answer:
28.00 g is the answer
Answer:200
Explanation:
It’s is the answer