Answer:
57.68
Explanation:
Last digit is 5 so we round of 7 to 8
Write the chief ore of sodium and potassium respectively?
Answer:
K-sylvite
Na-rock salt
Explanation:
Sylvite is a colourless or white mineral consisting of potassium chloride, occurring typically as cubic crystals(Oxford dictionary). It is the primary ore of potassium metal. It appears colorless, sometimes with a shade of red.
Rock salt is a primary ore of sodium. It is found in rocks, seas etc. Rock salt is sometimes commonly called halite. It usually appears white in colour and is rich in sodium.
what is the molecular formula of benzoyl peroxide (c7h5o2) of the molecular mass is 0.242 kg/mol?(show work please)
Answer : The molecular formula of benzoyl peroxide is [tex]C_{14}H_{10}O_4[/tex]
Explanation :
Empirical formula : It is the simplest form of the chemical formula which depicts the whole number of atoms of each element present in the compound.
Molecular formula : it is the chemical formula which depicts the actual number of atoms of each element present in the compound.
For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is :
[tex]n=\frac{\text{Molecular mass}}{\text{Empirical mass}}[/tex]
As we are given that the molar mass of compound is, 0.242 kg/mol.
Molecular mass = 0.242 kg/mol = 242 g/mol (1 kg = 1000 g)
The empirical mass of [tex]C_7H_5O_2[/tex] = 7(12) + 5(1) + 2(16) = 121 g/eq
[tex]n=\frac{\text{Molecular mass}}{\text{Empirical mass}}[/tex]
[tex]n=\frac{242}{121}[/tex]
[tex]n=2[/tex]
Molecular formula = [tex](C_7H_5O_2)_n[/tex] = [tex](C_7H_5O_2)_2[/tex] = [tex]C_{14}H_{10}O_4[/tex]
Thus, the molecular formula of benzoyl peroxide is [tex]C_{14}H_{10}O_4[/tex]
How many moles of nitrogen are in a 14.57 gram sample of nitrogen?
Answer:
[tex]\boxed {\boxed {\sf About \ 1.040 \ moles \ of \ nitrogen }}[/tex]
Explanation:
To convert from grams to moles, we must use the molar mass. This can be found on the Periodic Table. We have a sample of nitrogen, so look for N on the table.
Nitrogen (N): 14.007 g/molNow, use this molar mass as a ratio.
[tex]\frac {14.007 \ g \ N }{1 \ mol \ N }[/tex]
Multiply by the number of grams in the sample (14.57)
[tex]14.57 \ g \ N *\frac {14.007 \ g \ N }{1 \ mol \ N }[/tex]
Flip the fraction so the grams of nitrogen will cancel.
[tex]14.57 \ g \ N *\frac {1 \ mol \ N }{14.007 \ g \ N}[/tex]
[tex]14.57 *\frac {1 \ mol \ N }{14.007 }[/tex]
[tex]\frac {14.57 \ mol \ N }{14.007 }[/tex]
[tex]1.04019419 \ mol \ N \\[/tex]
The original measurement of grams had 4 significant figures, so we need to round our answer to the same number of sig figs.
For the number we calculated, that is the thousandth place. The 1 in the ten thousandth place tells us to keep the 0 in the thousandth place.
[tex]1.040 \ mol \ N[/tex]
There are about 1.040 moles of nitrogen in 14.57 grams.
Which material has been recycled for over 3,000 years?
Answer:
plastic
Explanation:
explain how transferring energy into or out of a substance changes the molecules kinetic energy and changes their freedom of movement
Answer:
Transferring energy into or out of a substance changes its temperature, which changes the molecules' freedom of movement. Claim 2: Transferring energy into or out of a substance changes the molecules' kinetic energy, which changes their freedom of movement.
Most of the carbon in the rocks that form Earth's mantle and crust was stored there when Earth formed. The rest of Earth's carbon is stored and exchanged in many ways.In a model of the carbon cycle, which process does NOT contribute directly to the storage of carbon within sediment?
Answer:
Photosynthesis.
Explanation:
In photosynthesis process, carbondioxide gas enters into plant leaves from which plant produces organic molecules such as glucose. This glucose helps the plant to increase it growth and complete development stages and finally the plant dies and buried in the soil so due to decomposition process, the carbon present in the plant body releases in the soil and become part of sediments. So indirectly photosynthesis process provides carbon to the soil.
What does the nucleus of an atom do to its own electrons? To the electrons of a nearby atom?
Why Do Some Things Stop While Others Keep Going?
Answer:because they run out of energy when it is transferred and to other objects, or their kinetic energy
Explanation:
A scientist has 207.45g of H2O in a beaker. How many water molecules are in the beaker?
Answer:
6.94 x 10²⁴molecules
Explanation:
Given parameters:
Mass of water = 207.45g
Unknown:
Number of molecules = ?
Solution:
To solve this problem, we must understand:
1 mole of a substance contains 6.02 x 10²³ molecules
Now, first find the number of moles of water;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of water = 2(1) + 16 = 18g/mol
Number of moles = [tex]\frac{207.45}{18}[/tex] = 11.53moles
So;
1 mole of a substance contains 6.02 x 10²³ molecules
11.53moles of carbon dioxide will contain 11.53 x 6.02 x 10²³
= 6.94 x 10²⁴molecules
A science teacher gave a student a sample of a clear liquid labeled "unknown
substance." Which property would best help the student determine the
sample's identity?
A. The sample's boiling point
B. The sample's mass
C. The sample's volume
D. The sample's weight
Answer:
A. The sample's boiling point
Explanation:
Because by knowing boiling point we easily find a substance for example if given clear liquid boiling point is 100 c° we immediately know this is water.
Moreover boiling point is a fixed quantity for a substance.
HELP PLEASE <3 !!!!!!
RODINNIS
COURSES
onal Science
Attempt 1 of 2
Which of the following distinctions are used to identify sedimentary rock? Select all that apply.
o where is was formed
conditions it was formed under
n when it was formed
what it is composed of
how many layers it consists of
NEED HELP ASAP (check the picture)
where it was formed and. conditions it was formed under
____ Al(NO3)3 + ____ FeCl2 --> _____ Fe(NO3)2 + ______AlCl3
~
how to fix/ balance this chemical reaction?
The balanced equation
2Al(NO₃)₃ + 3FeCl₂ ⇒ 3Fe(NO₃)₂ + 2AlCl₃
Further explanationGiven
Reaction
Al(NO₃)₃ + FeCl₂ --> Fe(NO₃)₂ + AlCl₃
Required
Balanced equation
Solution
Give a coefficient
aAl(NO₃)₃ + bFeCl₂ --> Fe(NO₃)₂ + cAlCl₃
Make an equation
Fe, left=b, right=1⇒b=1
N, left=3a, right=2⇒3a=2⇒a=2/3
Cl, left=2b, right=3c⇒2b=3c⇒2.1=3c⇒c=2/3
The equation becomes :
2/3Al(NO₃)₃ + FeCl₂ --> Fe(NO₃)₂ + 2/3AlCl₃ x3
2Al(NO₃)₃ + 3FeCl₂ --> 3Fe(NO₃)₂ + 2AlCl₃
Carbon Monoxide is a toxic gas that is colorless and tasteless. How many moles of CO are in 1 L of the gas at STP?
28 moles
0.045 moles
22.4 moles
0.224 moles
Answer:
0.045 moles
Explanation:
Given data:
Moles of CO = ?
Volume of gas = 1 L
Temperature and pressure = standard
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
n = PV/RT
n = 1 atm× 1L / 0.0821 atm.L/mol.K × 273 K
n = 1 atm.L / 22.41 atm.L/mol
n = 0.045 mol
Write a complete balanced equation for the following reaction:
magnesium metal reacts with oxygen gas
Explanation:
Given species:
Magnesium metals = Mg
Oxygen gas = O₂
Magnesium metal and oxygen gas are the reactants in this chemical process,
2Mg + O₂ → 2MgO
The product of the reaction is MgO because both oxygen and magnesium are divalent.
This reaction is called a combination reaction where two species combines to form a single compound.
Describe the brightness and temperature of the stars classified as giants.
Answer:
A hotter star should be brighter than a cooler star. ... Although they are cool [red], they are very luminous, and therefore bright. In the Main Sequence, stars that are cool are not as luminous. Because the energy is spread across a larger area, surface temperatures are actually cooler, reaching only 2,200 to 3,200 degrees Celsius (4,000 to 5,800 degrees Fahrenheit), a little over half as hot as the sun
Explanation:
Rico is doing an experiment. He makes a solution of calcium carbonate in a beaker of 200 mL of water at room temperature (25 °C). He adds a small amount of lemon juice to the solution and a chemical reaction begins. Rico reduces the temperature of the solution by 10 °C by adding ice. As the solution cools, what will happen to the chemical reaction?
The question is incomplete, the complete question is;
Rico is doing an experiment. He makes a solution of calcium carbonate in a beaker of 200 mL of water at room temperature (25 °C). He adds a small amount of lemon juice to the solution and a chemical reaction begins. Rico reduces the temperature of the solution by 10 °C by adding ice. As the solution cools, what will happen to the chemical reaction?
A. The chemical reaction will stop suddenly.
B. There will be no change in the rate of the chemical reaction.
C. The chemical reaction will slow as the water cools.
D. The speed of the chemical reaction will increase as the water cools.
Answer:
C. The chemical reaction will slow as the water cools.
Explanation:
The rate of a chemical reaction is dependent on the temperature of the reaction system. This derives directly from the collision theory of chemical reaction.
The higher the temperature of the system, the more frequently the particles collide and the faster the rate of reaction.
As the temperature is decreased, the rate of reaction decreases simultaneously. Therefore, as Rico decreases the temperature from 25 degrees to 10 degrees, the rate of reaction decreases accordingly.
Organisms that make energy are called ____.
Answer:
Producers
Explanation:
An autotroph is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. Because autotrophs produce their own food, they are sometimes called producers.
A doctor's order is 0.500 g of ampicillin. The liquid suspension on hand contains 250 mg/5.0 mL. How many milliliters of the suspension are required?
The volume of the suspension required : 10 ml
Further explanationGiven
0.500 g of ampicillin
The liquid suspension concentration = 250 mg/5 mL
Required
The volume of the suspension required
Solution
The concentration of a substance can be expressed in various units such as molarity, ppm, g / L etc.
Each unit change, we must pay attention to the conversion factor
Conversion g to mg
0.5 g = 500 mg
The volume of the suspension needed :
=mass x concentration
[tex]\tt \dfrac{500~mg}{250~mg/5~ml}=500~mg\times \dfrac{5~ml}{250~mg}\\\\=10~ml[/tex]
During ____, the chromatin condenses to make ____.
prophase, chromosomes
metaphase, chromosomes
prophase, DNA
metaphase, DNA
how can acids cause chemical weathering
The acids react with the chemical composition of the rock causes the disintegration of the rocks.
Chemicals when react with the chemical components of the rocks cause the disintegration of the chemical and physical structure of rocks which cause breakage of rocks into parts. This process is called chemical weathering.
For example, the sulfur dioxide gas in the air reacts with the water in the air to form the acid rain.
The acid rain reacts with the chalk or limestone rock that causes the disintegration of the chemical structure and physical structure of rock causing breakage of the chalk or limestone.
Learn more about weathering:
https://brainly.com/question/14426457
A student is drinking a cup of hot chocolate as they sit by a campfire on a chilly evening. They know that the cup of hot chocolate transfers thermal energy to the surrounding air. The heated air over their cup of hot chocolate expands and rises and is replaced by cooler, denser air.
This method of energy transfer is —
Answer:
A student is drinking a cup of hot chocolate as they sit by a campfire on a chilly evening. They know that the cup of hot chocolate transfers thermal energy to the surrounding air. The heated air over their cup of hot chocolate expands and rises and is replaced by cooler, denser air.
This method of energy transfer is
Explanation:
Answer:
radiation
Explanation:
radiation is when an existing heat source spreads heat to its surroundings
What are some properties we can use to describe matter
Answer:
melting point, hardness, odor, temperature
What is the pH of a 0.00001 M solution of HCI?
Answer:
0.00001= 1 x 10^-5. Since HCl is an acid, 1 x10^-5 is the H+ concentration. Write only the number of the exponent. Therefore, pH = 5.
Summarize the history of radioactivity by choosing the scientist(s) involved with each discovery.
conducted experiments with uranium-containing minerals and pure uranium.
came up with the term “radioactivity.”
showed that uranium in a mineral gave off radiation even without being exposed to the Sun.
discovered radium and polonium.
conducted experiments with fluorescent minerals and photographic plates.
Answer:
Marie and Pierre CurieMarie and Pierre CurieAntoine Henri BecquerelMarie and Pierre CurieAntoine Henri BecquerelExplanation: Correct on Edg 2020/2021.
When shark pups are small what do they eat
Answer:
The baby sharks are not connected to their mum through an umbilical cord. Instead, they feed on their egg's yolk supply, other unfertilized eggs or even the embryos of their brothers and sisters. Through the latter method, only the strongest 1-3 sharks will get born, which is seen in the sand tiger shark.
Explanation:
why is magneisum a metal
Answer:
Chemical element, metallic, symbol Mg, situated in group IIa in the periodic table, atomic number: 12, atomic weight: 24,312. ... Magnesium is known for a long time as the lighter structural metal in the industry, due to it's low weight and to it's capability of forming mechanically resistant alloys.
Calcium
and what
makes bones hard
What is this equation balanced?
CH4 + 2O2 =》CO2 + 2H2O
Answer:
the balanced chemical reaction is provided above .
Explanation:
the given reaction is reaction of methane with oxygen ( or burning of methane in presence of oxygen )
it is highly exothermic, because high amount of heat is evolved in this reaction
The burning of a sample of propane generated 1 04.6 kJ of heat. All of this heat was used to heat 500.0 g of water that had an initial temperature of 20.0/C. What was the final temperature of the water?
Answer: 70.0°C
Explanation:
Quantity of heat = Mass * Specific heat * Change in temperature
Quantity of heat = 104.6 KJ
Mass = 500.0 g
Specific heat of water is 4.18 J/g°C
Change in temperature assuming final temperature is x = x - 20
Units should be in grams and joules:
104,600 = 500 * 4.18 * (x - 20)
104,600 = 2,090 * (x - 20)
x - 20 = 104,600/2,090
x = 104,600/2,090 + 20
x = 69.8
= 70.0°C
