Answer:
Boiling Water
Explanation:
Boiling water is an example of physical change and not and not a chemical change because the water vapor still has the same molecular structure as liquid water.If the bubbles were caused by the decomposition of a molecule into gas then boiling would be a chemical change.
Answer:
A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding
Explanation:
How many grams are in 0.00321 mol NI
Solution
The mole is the number of particles contained in a substance
1 mol = 6.02.10²³
Moles can also be determined from the amount of substance mass and its molar mass
mol = mass : molar mass
mass = mol x molar mass
Molar mass = 58,6934 g/mol
Input the value :
mass = 0.0321 x 58,6934 g/mol
mass = 1.884 g
What are essential elements in plants?
Answer:
Chlorophyll is one. I can't quite remember other
Calculate the molality of an ethylene glycol (C2H6O2) soltuion, that has a molarity of 2.07 M. The density of the solution is 1.02 g/mL. Only enter the numerical value with 3 significant figures in the answer box below. Do NOT type in the unit (m).
Answer:
2.03
Explanation:
Let's assume we have 1 L of the solution:
There would be 2.07 ethylene glycol moles.The solution would weigh (1000 mL * 1.02 g/mL) = 1020 g.With that information we can calculate the molality:
molality = moles of solute / kg of solventmolality = 2.07 moles / (1020 ÷ 1000) = 2.03 mKeep in mind that this is only an estimate, as we used the kg of the solution and not of the solvent.
The molality of an ethylene glycol solution is 2.03 kg.
What is molality?The moles of solute divided by the mass of solvent in kilograms is known as the molality of a solution.
Calculation of molality:
Given that, molarity is 2.07 M
Density is 1.02 g/ml
Step 1: To convert the litre into grams, multiply the quantity by 1000
The weight of the solution is [tex]\bold{1.02 \;g/ml\; \times 1000 = 1020 g}[/tex]
Now, molality = moles of solute is divided by mass of solvent in kilograms.
[tex]\bold{Molality = 2.07 \times \dfrac{1020}{1000} = 2.03\; kg}[/tex]
Thus, the molality of the solution is 2.03 kg
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molality = moles of solute / kg of solvent
molality = 2.07 moles / (1020 ÷ 1000) = 2.03 m
Keep in mind that this is only an estimate, as we used the kg of the solution and not of the solvent.
Earths outer core is made of ___
Answer:
iron and nickel (liquid metal )
Explanation:
The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances. The outer core is responsible for Earth’s magnetic field. As Earth spins on its axis, the iron inside the liquid outer core moves around
Answer:
The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances.
Explanation:
What is the answer for number 9 in the Half-life gizmo activity B.
How many carbon atoms are represented by Mg(HCO3)
383.2 K to degrees Celsius
Answer: 110.05
Explanation: i dont know i looked it up
Which of the following materials will conduct electricity well?
Cotton
Metal
Rubber
Wood
Answer:
Metal
Explanation:
Rubber and Wood are insulators. and Cotton is neither a insulator nor a conductor. But Metals are conductors
Question asked: Which of the following materials will conduct electricity well?
Answer: Metal
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I hope this helps!
You find yourself in a room with dark gray walls. Medeleev’s image says, “This element is essential for plant life to thrive and is found in heavy clay minerals and the ash from your campfire.” What element are these walls made from?
Answer:
juvn hgf jb ujvi i junk food sux
Explanation:
Select the BEST definition for entropy. Select one: a. stored energy in a substance that is exchanged as heat during a reaction (at constant pressure). b. tendency for a substance to achieve maximum disorder (i.e., randomly distribute). c. state of balance between a forward and a reverse reaction. d. ability of an atom to attract electrons for bonding.
Answer:
b. tendency for a substance to achieve maximum disorder (i.e., randomly distribute).
Explanation:
Entropy can be defined as the tendency for a substance to achieve maximum disorder (i.e., randomly distribute).
This ultimately implies that, entropy is a thermodynamic quantity that measures the degree of maximum order or randomness of a system.
The S.I unit used for the measurement of the degree of maximum order or randomness of a system is Joules per Kelvin (JK¯¹). An example of entropy is the mixing of ideal gases.
The diagram shows the electron configuration around the chlorine nucleus. Chlorine has 17 protons.
CI
Which of the following correctly completes the statement?
Chlorine has valence electrons, and the effective nuclear charge, Zett, for the chlorine atom shown is
O A. 7,7+
OB. 7,7-
O C. 10,7-
D. 17, 7+
Answer: A. [tex]7,+7[/tex]
Explanation:
Valence electrons are the number of electrons constituting the outermost shell of an atom. It is also defined as the electrons that take part in the formation of a chemical bond.
The atomic number of chlorine is 17 as it has 17 protons and the electronic configuration will be 2,8,7. Thus the electrons present in the outermost shell are 7 and hence the valence electrons are 7.
Effective nuclear charge is the net positive charge experienced by valence electrons. It is calculated by: Zeff = Z – S
where Z = atomic number , S = number of shielding electrons.
Thus for Chlorine , [tex]Z_{eff}=17-10=7[/tex]
What is the difference between a proton, neutron, and electron?
Answer:
proton :
a particale or atom containing a postive charge
nuutron
a particale or atom that contains a negative charge
electron :
a particale or atom with a negative chrage.
Explanation:
proton:
a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.
nuetron:
a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
elcetron:
a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.
Which color of light does a green object absorb?
Answer:
Magenta.
Explanation:
Color absorption is a process that occurs when a light wave strikes an object. When a light wave strikes an object it either absorbs color or transmits the color, or reflects the color. When a light wave strikes a green object, it absorbs a magenta color.
Magenta is a combination of red and blue light, therefore, the colors that the green object will absorb is red. blue, or magenta light.
11) How many moles of CO2 can be produced from
5.0 moles of O2?
Answer:
3.6 moles
Explanation:
5.0moles produce 44g/x will produce 32g the answer is a3.6moles
In chemical reactions, a product is
Select one:
any substance that is made from the least number of atoms
any substance to the right of the arrow
any substance that is made of the greatest number of atoms
ubstance that s to the left of the arrow
a certain kind of pea plant has an allele for tall and an allele for short but its overall phenotype is tall.
Answer:
Tt
Explanation:
T= Dominant tall
t= non-dominant short.
Dominant always shows over non-dominant.
g A and B are both non-volatile molecular compounds. Substance A has a greater molar mass than substance B. If 50 g of substance A are dissolved in 250 g of water in one beaker, and 50 g of substance B are dissolved in 250 g of water in another beaker, then which ONE statement below will be true? A) the vapor pressure of solution A will be lower than the vapor pressure of solution B. B) the solution of A will freeze at a lower temperature than the solution of B. C) the two solutions will have the same vapor pressure. D) the boiling point of solution A will be lower than the boiling point of solution B. E) the solution of A will have a higher osmotic pressure than the solution of B.
Answer:
The correct answer is - option D. the boiling point of solution A will be lower than the boiling point of solution B
Explanation:
Colligative properties such as a decrease in the freezing point of the solution, increase in the boiling point of substance, decrease in Lowering of vapor pressure, and other properties depend upon the number of molecules only.
In the given solution the equal amount of two solutions are mixed that is 50 grams however due to the difference in the molecular mass so the atoms present in both solution A and B will be different. It is known that the number of atoms of a substance is inversely proportional to the molecular mass of the particular substance.
As it is given that Solution B has a low molecular mass which means it has a high number of atoms that means its boiling point will be higher than solution A.
Use the periodic table to select the element that best fits each of the following descriptions.
Noble gas:
O oxygen
O chlorine
Okrypton
Answer:
Krypton
Explanation:
A solution is prepared by dissolving 10.6 g sodium carbonate in enough water to produce
500.0 mL solution. What is the molarity of sodium carbonate in the solution?
Answer:
0.2mol/dm³
Explanation:
Given parameters:
Mass of Na₂CO₃ = 10.6g
Volume of solution = 500mL
Unknown:
Molarity of solution = ?
Solution:
The molarity of a solution can be determined using the expression below:
Molarity = [tex]\frac{number of moles }{volume}[/tex]
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol
Number of moles = [tex]\frac{10.6}{106}[/tex] = 0.1mol
Convert mL to dm³;
500mL will give 500 x 10⁻³dm³or 0.5dm³
So;
Molarity = [tex]\frac{0.1}{0.5}[/tex] = 0.2mol/dm³
The proper dosage of a certain medication is 0.50 mg per kilogramof of patient weight. The medication is the Spence in a liquid that contains 350.0ug of medication per mL of liquid. What volume of liquid medication should be given to a 183 Ib patient. (1kg= 2.204 lb)
Answer:
118.61 mL.
Explanation:
Hello!
In this case, since we know the concentration in the medication:
[tex]\frac{350.0\mu g}{1mL}[/tex]
Now, since there are 0.50 mg of the medication per kilogram of patient, we can compute the volume as shown below for a 183-lb patient:
[tex]183lb*\frac{1kg}{2.204lb}* \frac{0.50mg}{1kg} *\frac{1000\mu g}{1mg} *\frac{1mL}{350.0\mu g} =118.61mL[/tex]
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WORTH 35 POINTS! MY LIFE DEPENDS ON IT HELP!
When naming ionic compounds, always
1. use prefixes
2. write the metal first
3. write the nonmetal first
4. capitalize the metal and nonmetal
Answer
2.Write the metal first ( if I am right) as it is ionised
a reaction vessel contains a small piece of magnesium metal and air (20%) of which is oxygen gas. The mixture is ignited and burns with a burst of light and heat, producing solid magneisum oxide. The mass of mgO, however, is less than the initital mass of magnesium and oxygen combined. What loss of mass
Answer: see below
Explanation:
Mg burning in air gives MgO and a smaller amount of Mg3N2
2Mg+O2=2MgO. 2*24.3+32=2*40.3
3Mg+N2=Mg3N2
Ignoring the nitride, MgO loss of mass during the reaction can be ascribed to
(1) relativistic loss as energy (too small to be measurable)
(2) During the reaction, which is strongly exothermic, a fraction f the material is blown off as tiny particles which adhere to the vessel.
In a heterogeneous chemical reaction requiring the use of a solid catalyst, the rate of the reaction could not be increased by increasing the concentration of reactants, but was doubled by doubling the amount of solid catalyst added. This probably indicated that
Answer:
The active sites on the initial amount of catalyst were fully saturated
Explanation:
A catalyst is a substance which alters the rate of a chemical reaction but largely remains unaltered at the end of the reaction. A catalyst has an active site which enables it to catalyze a reaction.
The active site provides the best possible orientation for reactant molecules to collide in order to form products.
When the active sites are not fully saturated with reactant molecules, more reactant molecules can bind and the reaction can proceed much faster. However, if the active sites of the catalysts are fully saturated, the reaction has maximum velocity and cannot go anymore faster.
Addition of more catalyst molecules can however make the reaction proceed faster as a it provides more active sites for reaction for the reactants.
6. Describe nuclear fusion reactions as they
occur in the sun.
Answer:
i wish i know
Explanation:
i wish i know
True or false questions?
Most metal elements are brittle and do not conduct electricity. True or False
Any element can be identified by counting the protons in its neucleus. True or False
All Earths matter is made from the combination of about 100 elements. True or false
Answer:
1. False 2.True3.True? Unsure
Explanation:
which statement is true about both groundwater and surface water?
A. Rainwater forms both the groundwater and the surface water
B. The water levels of both the groundwater and the surface water stay stable
C. Both the groundwater and the surface water are purified as they soak through the soil layers
D. The groundwater and the surface water together form a drainage basin
The statement which is true about both groundwater and surface water is that the groundwater and the surface water together form a drainage basin.
What is ground water?
Ground water is the type of water which is present below the surface of rock and between spaces in soil pores .Thirty percent of the available fresh water is present in the form of groundwater.
Groundwater is discharged from the surface naturally in the form of springs and seeps and can also exist in the form of oases or wetlands.It is used for various purposes like for agriculture, municipal and industrial uses. They are used by constructing wells .
The study of movement and distribution of ground water is called hydrogeology or even groundwater hydrology.It is a cheaper source of water and is less prone to pollution as compared to surface water.
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Suppose of nickel(II) bromide is dissolved in of a aqueous solution of potassium carbonate. Calculate the final molarity of nickel(II) cation in the solution. You can assume the volume of the solution doesn't change when the nickel(II) bromide is dissolved in it. Round your answer to significant digits.
The question is incomplete, the complete question is;
Suppose 1.87g of nickel(II) bromide is dissolved in 200.mL of a 52.0mM aqueous solution of potassium carbonate. Calculate the final molarity of nickel(II) cation in the solution. You can assume the volume of the solution doesn't change when the nickel(II) bromide is dissolved in it. Be sure your answer has the correct number of significant digits. The answer is needed in M.
Answer:
0.0428 M
Explanation:
The equation of the reaction is;
NiBr2 + K2CO3 → NiCO3 + 2KBr
Number of moles of NiBr2 = mass/molar mass = 1.87 g/218.53 g/mol =
8.557 * 10^-3 moles
Now, we know that the Ni^2+ comes from the NiBr2. Also, the concentration of Ni^2+ in NiBr2 = concentration of Ni^2+ in NiCO3
So,
Concentration of Ni^2+ = 8.557 * 10^-3 moles/0.2 L = 0.0428 M
what are the three important properties of acids
What are the different elements that make up a molecule of glucose?
Answer:
Glucose has a chemical formula of: C6H12O6 That means glucose is made of 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms. You will be building one type of sugar called glucose.
Explanation:
How many mols of NaOH are there in 10 grams of NaOH? *
Answer:
0.25 moles
Explanation:
The molar mass of NaOH is 40 g/mol.
[tex]\frac{10g}{40g/mol}[/tex] This equals 0.25 moles
