Answer:
Molarity = 0.72M
Molality = 0.85M
Explanation:
Molarity and molality are two measures of molar concentration, and they can be calculated as follows:
Molarity = number of moles/volume of solvent
Molality = number of moles/mass (kg) of solvent
Mole = mass/molar mass
Molar mass of stilbene (C14H12) = 12(14) + 1(12)
= 168 + 12
= 180g/mol
mole of stilbene = 13/180
mole = 0.072mol
Volume = 100mL = 0.1L
molarity = 0.072/0.1
Molarity = 0.72M
Molality = number of moles ÷ mass (kg) of solvent
To get mass of solvent, we use;
Density = mass/volume
Mass = density × volume
Mass = 0.85g/mL × 100mL
Mass = 85g
Mass in kg = 85/1000 = 0.085kg
Molality = 0.072/0.085
Molality = 0.847M
Molality = 0.85M
When solid materials are heated.the heat absorbed/added to the materials caused the materials to change its form
Complete question is;
When solid materials are heated.the heat absorbed/added to the materials caused the materials to change its form from?
Answer:
From solid to liquid
Explanation:
When we heat solid materials, the heat causes the forces of attraction between the molecules to become weaker and as such, the material becomes more loose than it was in the solid state. As a result, the material now becomes a liquid because the molecules now have lesser forces of attraction and are a bit loose.
Which of the following is a common cause of acid rain? *
1 point
oil spilled into tropical ocean waters
gases released when plants make food
emissions produced by burning fossil fuels
warm water released from nuclear power plants
Answer:
Emissions produced by burning fossil fuels
Explanation:
these gases decreases the ph level of rain water that makes water acidic
How to find specific heat capacity of a liquid
Answer:
Heat Capacity = E / T.
- Find the difference in temperature for changes of multiple degrees.
- Add the appropriate units to your answer to give it meaning.
- Know that this equation works for cooling objects as well.
- Know that specific heat refers to the energy needed to raise one gram by one degree.
____ is the amount of matter in an object. Question 1 options: Matter Gravitational Pull Mass Weight
Answer:
It's Mass
Explanation: I took the quiz
Have a good day!
Mass is the amount of matter in an object. Therefore, option C is correct.
What is mass?Mass can be defined as an intrinsic property of a body. mass can be described as the quantity of matter in a body. Different atoms and different particles with the same amount of matter have nonetheless different masses.
Mass can be experimentally measured by the body's inertia, meaning the resistance to acceleration when a net force is applied. The mass determines the strength of its gravitational attraction to other bodies.
The SI base unit of measurement of mass is the kilogram (kg) and it is not the same as weight. Mass is generally determined by measuring the weight using a spring scale, rather than a balance scale and comparing it to known masses.
An object on the Moon will weigh less than it does on Earth due to the lower gravity but still have the same mass. Weight can be defined as a force, while mass is the property that determines the strength of this force.
Learn more about mass, here:
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How many moles are in 230 grams of calcium phosphate
Answer: 0.74 moles
Explanation:
The first step is to figure out the chemical formula for calcium phosphate. Since we know that calcium is a metal, this will be an ionic bond. Calcium is written as Ca and has a charge of +2. Phosphate is written as PO4 with a charge of -3. To come up with the subscripts for this formula, cross the charges. That means that you will get [tex]Ca_{3} (PO_{4} )_{2}[/tex].
Next, calculate how many grams one molecule of calcium is. Calcium has an atomic weight of 40, and there are 3 molecules of calcium, so 40 x 3 = 120. Phosphorus has an atomic weight of 31, and there are 2 molecules of phosphorus, so 31 x 2 = 62. Oxygen has an atomic weight of 16, and there are 8 molecules of oxygen, so 16 x 8 = 128. Adding all of those together gives you 310 g.
Now, using stoichiometry, we can figure out the question. We know that there are 230 grams. We also know that one mole weighs 310 g. If you divide 230 by 310, you will get your answer, which is 0.74 moles.
what is the sum of 16+ -20?
answer:
-4
hope this helps
Calcium hydroxide is sprayed on acidic gas produced by power stations. The acidic gas is sulfuric acid. What is the word equation between calcium hydroxide and sulfuric acid?
Answer:
wait so dose it acid burn your body I would say hydrogen but I'm probably wrong tell me if I am
What is a stock solution?
Select one:
ca. A concentrated solution that is used to make a more concentrated solution.
b. A concentrated solution that is used to make diluted solutions.
c. A solution that has been diluted to a concentration of exactly 1 M.
ND d. A solution that has been diluted to a concentration of less than 1 M.
You can increase a step-up transformer's voltage with
A. a power source connected to the primary coil
B. a source connected to the secondary coil.
C. increasing the number of loops in the primary coil.
D. increasing the number of loops in the secondary coil
Answer:
A. a power source connected to the primary coil
Explanation:
According to Charles's law, what will happen to the volume of these balloons as temperature
increases?
Balloons
The volume will increase and the balloons will be bigger.
O The volume will decrease and the balloons will be smaller.
The volume and balloon size will both stay the same.
Answer:
The volume will decrease and the balloons will be smaller
Find the slope of BG, and HL using the coordinates; B(–4, 3), G(–2, 4), H(1, –2), L(–1, –3). then determine if the lines are parallel.
Answer:
Explanation:
The chemical reaction shown is called photosynthesis. It involves water reacting with carbon
dioxide to produce glucose (see formulae below) and another gas. The chlorophyll in leaves
acts as a catalyst. ON A PIECE OF PAPER. Write a (BN level) word equation. (G Level)
Equation with formulae. (P-E) Balanced chemical equation with states.*
CoH1206
Answer:
See explanation
Explanation:
A word equation refers to a representation of a chemical process using word rather than appropriate chemical formulae.
Hence, the word equation for photosynthesis is this;
six moles of carbon dioxide + six moles of water -----> one mole of glucose + six moles of oxygen gas
The equation with formulae is;
6CO2 + 6H20 -------> C6H1206 + 6O2
Balanced chemical equation with states;
6CO2(g) + 6H20(l) -------> C6H1206(s) + 6O2(g)
Copper (ii) carbonate decomposes to form copper (ii) oxide grains and carbon dioxide gas is given off.
Answer:
yes
Explanation:
The correct equation for the decomposition of copper carbonate is:
CuCO3 → CuO + CO2
Use the half-reaction method to balance the following equations :
MnO4- + Br- = MnO2 + BrO3- (Acidic Solution )
Br- + 2MnO4- + 2H+ → BrO3- + 2MnO2 + H2O
Further explanationGiven
MnO4- + Br- = MnO2 + BrO3-
Required
The half-reaction
Solution
In acidic conditions :
1. Add the coefficient
2. Equalization O atoms (add H₂O) on the O-deficient side.
3. Equalization H atoms (add H⁺ ) on the H -deficient side. .
4. Equalization of charge (add electrons (e) )
5. Equalizing the number of electrons and then adding the two half -reactions together
Oxidation : Br- → BrO3-
Reduction : MnO4- → MnO2
Equalization O atomsBr- + 3H2O → BrO3-
MnO4- → MnO2 + 2H2O
Equalization H atomsBr- + 3H2O → BrO3- + 6H+
MnO4- + 4H+ → MnO2 + 2H2O
Equalization of chargeBr- + 3H2O → BrO3- + 6H+ + 6e- x1
MnO4- + 4H+ + 3e- → MnO2 + 2H2O x2
Equalizing the number of electrons and then adding the two half -reactions togetherBr- + 3H2O → BrO3- + 6H+ + 6e-
2MnO4- + 8H+ + 6e- → 2MnO2 + 4H2O
Br- + 2MnO4- + 3H2O + 8H+ + 6e- → BrO3- + 2MnO2 + 6H+ + 4H2O + 6e-
Br- + 2MnO4- + 2H+ → BrO3- + 2MnO2 + H2O
Suppose you have a mixture of iron filings, sand, and sugar and you want to separate the three. Fill in the materials you expect to see at each step as you perform the actions shown to separate them. The materials you may expect to see are: iron filings, sand, sugar, and sugar water.
Answer:
Explanation:
mixture of iron filings, sand, and sugar
First Step - Iron Fillings
Use a magnet to separate the iron fillings from the mixture. Due to magnetic properties of the iron fillings, the magnets would attract the iron fillings and separate it from the mixture.
Second step - Sand
Place the sand and sugar mixture in water. The sugar would dissolve in water and the sand easily separated by filtration.
Third step - Sugar and Sugar water
Boil the sugar water to remove the water and place in the refrigerator for crystallization of the sugar.
The electron configuration of an element is 1s22s2. How many valence electrons does the element have? (1 point) a 1 b 2 c 3 d 4
Answer:
b
Explanation:the shell is 2 so ignore the 1s electrons it is only the level 2 electrons that are valence
I really need help, I don’t know what to do on this
Answer:
A: dependent variable
B: experimental group
C: independent variable
D: control variables
E: control group
Explanation:
Place the
elements in order from low number of valence electrons to high number of valence electrons.
1
Neon
2
Aluminum
3
Silicon
4.
Potassium
5
Magnesium
4. Calculate the number of carbon (C) atoms present in the 25 mL of sugar.
Show all your workings
*
Answer: [tex]8.38\times 10^{23}atoms[/tex] of carbon
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
mass of sugar= [tex]density\times volume=1.59g/ml\times 25ml=39.75g[/tex]
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{39.75g}{342.3g/mol}=0.116moles[/tex]
1 mole of sugar [tex]C_{12}H_{22}O_{11})[/tex] contains = [tex]12\times 6.023\times 10^{23}=72.28\times 10^{23}atoms[/tex] of carbon
0.116 mole of sugar [tex]C_{12}H_{22}O_{11})[/tex] contains = [tex]\frac{72.28\times 10^{23}}{1}\times 0.116=8.38\times 10^{23}atoms[/tex] of carbon
Select the boxes next to three properties that are typical of metals ??PLS I Will GIVE BRAINLY TO FIRST
Answer:
option b is correct
Explanation:
Metals are particularly good conductors of heat because their particles are very closely packed so the vibrations are passed on very quickly. They also contain large numbers of free electrons. These drift slowly through the structure, giving metals their strength and other properties. As the metal is heated, the free electrons closest to the heat source are heated. This makes them move faster and they travel through the metal, colliding with both atoms and other electrons. This naturally makes these vibrate faster (or move through the metal faster in the case of collisions with other free electrons). Thus, the heat is passed quickly through the metal.
hope it helps you
please mark me as brainlist
3. Describe what happens to chemical bonds as a chemical reaction is taking place.
4. Give 3 examples on a daily basis of chemical reactions.
5. What is the difference between a chemical formula and a chemical equation?
Answer:
1. In a chemical reaction, the atoms and molecules that interact with each other are called reactants. ... No new atoms are created, and no atoms are destroyed. In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
2. Given below are some of the examples of the chemical reactions in our daily life:
Photosynthesis.
Combustion.
Aerobic cellular respiration.
Anaerobic respiration including the process fermentation.
Metathesis reactions, for example, vinegar and baking soda.
Oxidation which includes rusting.
Digestion.
3. A chemical formula is the combination of atomic symbols that designate a particular chemical compound, or a substance with two or more different elements. ... A chemical equation shows one or more chemical compounds (reactants) being converted into different chemical species called products.
Which volume is the greatest?
Microliter
Milliliter
Deciliter
Centiliter
Answer:
Deciliter = 0.1 L
Explanation:
The options are unit of volume. In order to determine which is greatest, all the options would be converted to liter.
Microliter = 1e-6 L
Mililiter = 0.001 L
Deciliter = 0.1 L
Centiliter = 0.01 L
Among all the options; Deciliter = 0.1 L is the greatest.
Pl help it’s for a grade I will give Brainly if right
Answer:
A. moving
Explanation:
How many moles is 287.7 grams of Iridium (Ir)?
1.497 mol Ir
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
287.7 g Ir
Step 2: Identify Conversions
[PT] Molar Mass of Ir - 192.22 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 287.7 \ g \ Ir(\frac{1 \ mol \ Ir}{192.22 \ g \ Ir})[/tex]Multiply/Divide: [tex]\displaystyle 1.49672 \ mol \ Ir[/tex]Step 4: Check
Follow sig fig rules and round. We are given 4 sig figs.
1.49672 mol Ir ≈ 1.497 mol Ir
Answer:
[tex]\boxed {\boxed {\sf About \ 1.497 \ mol \ Ir }}[/tex]
Explanation:
To convert from grams to moles, we must the molar mass of iridium, which can be found on the Periodic Table.
Ir: 192.22 g/molUse the molar mass as a ratio.
[tex]\frac{ 192.22 \ g \ Ir}{ 1 \ mol \ Ir}[/tex]
Multiply by the given number of grams: 287.7
[tex]287.7 \ g Ir *\frac{ 192.22 \ g \ Ir}{ 1 \ mol \ Ir}[/tex]
Flip the fraction so the grams of Iridium will cancel.
[tex]287.7 \ g Ir *\frac{1 \ mol \ Ir }{ 192.22 \ g \ Ir}[/tex]
[tex]287.7 *\frac{1 \ mol \ Ir }{ 192.22 }[/tex]
[tex]\frac {287.7 \ mol \ Ir }{192.22} \\[/tex]
Divide.
[tex]1.49672251 \ mol \ Ir[/tex]
The original measurement has 4 significant figures, so we must round our answer to 4 sig figs as well. For the answer we calculated, that is the thousandth place.
The 7 in the ten thousandth place tells us to round the 6 up to a 7.
[tex]1.497 \ mol \ Ir[/tex]
There are about 1.497 moles of iridium in 287.7 grams.
What is the concentration in molL-1 of 20 mL of Na2CO3 solution that neutralises 15 mL of 1 M HCl solution?
Answer:
[tex]0.75\ \text{M}[/tex]
Explanation:
[tex]C_1[/tex] = Concentration of [tex]Na_2CO_3[/tex]
[tex]C_2[/tex] = Concentration of [tex]HCl[/tex] = 1 M
[tex]V_1[/tex] = Volume of [tex]Na_2CO_3[/tex] = 20 mL
[tex]V_2[/tex] = Volume of [tex]HCl[/tex] = 15 mL
We have the relation
[tex]V_1C_1=V_2C_2\\\Rightarrow C_1=\dfrac{V_2C_2}{V_1}\\\Rightarrow C_1=\dfrac{15\times 1}{20}\\\Rightarrow C_1=0.75\ \text{M}[/tex]
The concentration of [tex]Na_2CO_3[/tex] is [tex]0.75\ \text{M}[/tex].
6) Using the rules for significant figures, the sum of 0.027 gram
and 0.0023
gram should be expressed as
A) 0.030 gram B) 0.0293 gram C) 0.029 gram D) 0.03 gram
I need help
Answer:
it would be C
Explanation:
Answer: C
Explanation:
both numbers have 2 S.F. so the answer should have 2 too.
13.Which shows the order of increasing ionization energy?
a.Si, Al, Mg, Na
b.Ga, Ge, As, Se
c.Be, Mg, Ca, Sr
d.F, Cl, Br, I
3 10.0 grams of granite is heated from 30 °C to 50 °C . How much energy does this require? The specific heat of granite is 0.79J/goC
Answer:
The energy required is 158 J
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
When the heat added or removed from a substance causes a change in temperature in it without affecting its molecular structure, this heat is called sensible heat.
In other words, when a system absorbs (or gives up) a certain amount of heat, it can happen that it experiences a change in its temperature, which implies sensible heat.
The equation that allows calculating heat exchanges is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case:
c=0.79 [tex]\frac{J}{g*C}[/tex]m= 10 gramsΔT= Tfinal - Tinitial= 50 C - 30 C= 20 CReplacing:
Q= 0.79 [tex]\frac{J}{g*C}[/tex] *10 g* 20 C
Solving:
Q= 158 J
The energy required is 158 J
Energy used for metabolism comes primarily from which biomolecules a) Polysaccharides only b) Lipid only c) Lipid and Carbohydrates D) amino acids
Answer:
C) Lipids and Carbohydrates
Explanation:
Lipids, or fats, are stored long-term for energy when an organism cannot find carbohydrates (specifically glucose), which are used as short-term energy.
4. What causes a partial lunar eclipse?
Answer:
A partial lunar eclipse occurs when only a portion of the Moon enters Earth's umbra, while a total lunar eclipse occurs when the entire Moon enters the planet's umbra.