Answer:
The answer is
1.204 × 10²⁴ moleculesExplanation:
The number of molecules can be found by using the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 2 × 6.02 × 10²³
We have the final answer as
1.204 × 10²⁴ moleculesHope this helps you
radium 226 has a half life of 1600 yers. suppose we have a 300g sample. how much remains after 200 years
Answer:
[tex]A=275.1g[/tex]
Explanation:
Hello.
In this case, since the radioactive decay is computed via:
[tex]A=A_0*2^{-\frac{t}{t_{1/2}}[/tex]
For the initial amount of Ra-226 (300 g), once 200 years have passed, the remaining mass is:
[tex]A=300g*2^{-\frac{200years}{1600years}}\\\\A=275.1g[/tex]
This is, considering that the half-life is 1600 years, it means that the mass of Ra-226 is decreased.
Best regards.
A mineral breaks into cubes when struck with a rock hammer. It also leaves a red trail when scraped against an unglazed porcelain plate.
Which of the mineral's properties are being measured?
Choose the two correct answers.
streak
color
cleavage
hardness
The two properties which can be measured from the given information are streak and cleavage of the mineral.
What are minerals?Minerals are naturally forming inorganic substances having crystal structure and metallic characteristics. They have a definite chemical composition and homogeneity.
Streak is the color of powder form of mineral and cleavage is how the mineral cleave when we cut through a plane. Hardness says how much hard the solid is.
When the mineral breaks into cubes when struck with a hammer, we measure its cleavage properties. The red trail on scrapping indicates the streak of the mineral.
Hence, the two properties we can measure from breaking by hammer and scrapping by an unglazed porcelain are its cleavage and streak.
To learn more about minerals, refer the link below:
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Convert 5.4g of NaCl to moles
Answer:
.0924 moles of NaCl
Explanation:
So you know you have 5.4 g of NaCl and you need to know how many moles there are in this amount of NaCl
You'll need to find the atomic mass of the compound NaCl to help you solve for moles Sodium (Na) on the periodic table has a mass of 22.99 Chlorine (Cl) on the periodic table has a mass of 35.45Add these two together----> 22.99 + 35.45 = 58.44
Now you can calculate for moles
Written-out method:
5.4 grams of NaCl | 1 mole of NaCl
| 58.44 grams NaCl = .0924 moles of NaCl
Plug into calculator method:
(5.4 g of NaCl/ 58.44g NaCl= .0925 moles)
2.
_______ properties depend on the amount of
matter present
Answer:
extensive properties
Explanation:
,such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity.
I NEED HELP ASAPPPP!!!!
Is a styrofoam ball heavier than a rock?
Is water heavier than a ping pong ball?
Is a gold ring heavier than a pencil?
Is oil heavier than water?
Is a large log heavier than a small rock?
Answer:
Styrofoam could be heavier than a rock depending on how much weight you put on it,
Water is heavier than a ping pong ball,
A gold ring is not heavier than a pencil,
Oil is heavier than water because of the combined mass.
A large log is heavier than a small rock.
Explanation:
what is the volume in cubic meter and in cubic decimeter of 2.0mol of nitrogen on gas at 1000c and 100,000pa? (R=8.31j/molk)
Given parameters:
Number of moles of Nitrogen = 2.0mole
Temperature of the gas = 1000c
Pressure on the gas = 100000Pa
Gas constant R = 8.31J/molK = 0.082atmdm³mol⁻¹k⁻¹
Unknown:
Volume in cubic meter and cubic decimeter = ?
Solution:
The ideal gas law is given as;
PV = nRT
where P is the pressure on the gas
V is the volume of the gas
n is the number of moles
R is the gas constant
T is the temperature of the gas
Let us convert to appropriate units;
1000°C to K;
K = 1000 + 273 = 1273K
100000Pa to atm;
101325Pa = 1atm
100000Pa = 0.99atm
Input the parameters and solve for the unknown;
0.99 x V = 2 x 0.082 x 1273
V = 210.9dm³
to m³;
1000dm³ = 1m³
210.9dm³ = [tex]\frac{210.9}{1000}[/tex] = 0.21m³
HELPP
35. A catalyst:
a. actually participates in the reaction.
b. changes the equilibrium concentration of the products.
c. decreases the rate for a reaction.
d. increases the activation energy for a reaction.
If you are given 22.990 g of sodium and 12.011 g of carbon, which sample do you expect to have more particles?
Answer:
they are expected to have the same particles because their masses are the same with there molar mass
Answer quick (image)
Answer:
The answer is boiling point
can someone help me im doing chemistry right now and I have a question which I have no idea how to solve and I need to show work it it needs to be shown in scientific notation
(7.6x10^-1)+(2.0x10^-2)
When an atom is trying to obtain stability, what part(s) of the atom change(s)?
Answer: If the outer shell is filled, the atom is stable. Atoms with unfilled outer shells are unstable, and will usually form chemical bonds with other atoms to achieve stability.
(hope this helps ^^)
What ingredients can be alternative for cornstarch?
Answer:
their are many alternative for cornstarch.But I know only 10 of them and they are:
1.Rice Flour
2.wheat Flour
3.Potato Starch
4.Arrowroot
5.Tapioca
6.Ground Flaxseeds
7.Gaur Gum
8.Xanthan Gum
9.Glucomannan
10.Xanthan Gum
How many total hydrogen atoms are in CH3OOH?
Answer:
4
Explanation:
In CH3OOH, there is H3, which means 3 hydrogen atoms, but there is also an H at the end, which means another hydrogen atom.
3 + 1 = 4
Weather is not the same as climate. Which claim
identifies the main difference between these two concepts?
A. The main difference is how both are measured
B. Only weather includes information about the
temperature
C. Only climate includes information about
precipitation
O D. The main difference is the length of time over
which both are measured
Answer:
b. only weather includes information about the temperature
chemistry question please help
Answer:
AR(18)
Explanation:
Try that it should work
*(
If you do not recall the exact date of an event, it is okay to use a general time reference instead.
Please select the best answer from the choices provided
T
F
Answer:
True
Explanation:
Sorry if this is late lol
Answer:
The answer is True.
Explanation:
Did not copy
Helppppppp plssss guysss
Answer:
3 - coefficient
2 subscripr
6 total #
cl- element symbol
D 14 3
N
7
What is the number of protons, neutrons, and electrons?
Answer:
14
Explanation:
For example, silicon has 14 protons and 14 neutrons. Its atomic number is 14 and its atomic mass is 28. The most common isotope of uranium has 92 protons and 146 neutrons. Its atomic number is 92 and its atomic mass is 238 (92 + 146).
The human eye cannot see anything less than 40 micrometers in size. What is this length in meters?
Answer:
4e-5 is the length in meters
Have a nice day! :)
A sample of ammonia gas has a volume of 3213 mL at 11°C and a pressure of 822 torr. What will the volume of the gas be in liters if the
moles of gas and the temperature do not change but the pressure changes to 2.33 atm?
Answer:
We are given:
v1 = 3.2 L v2 = x L
p1 = 822 torr OR 1.08 atm p2 = 2.33 atm
t1 = t2 = 284 k
From the Ideal gas equation:
PV = nRT
Since the number of moles (n), universal gas constant (R) and Temperature (T) are constant
PV = k (where k is a constant)
it can also be written as:
P1V1 = k --------------------------(1)
Similarly,
P2V2 = k (where k is the same constant as before)----------(2)
Solving for V2:
From (1) and (2):
P1V1 = P2V2
Replacing the variables
1.08 * 3.2 = 2.33 * x
x = (1.08 * 3.2)/2.33
x = 1.5 L (approx)
Therefore, the final volume of the solution will be 1.5L
A balloon containing methane gas has a volume of 1.03 L at 99.0 °C . What volume will the balloon occupy at 198 °C ?
Answer:
The balloon will occupy a volume of 1.32L.
Explanation:
Given the following data;
Original Volume, V1 = 1.03L
Original Temperature, T1 = 99°C
New Temperature, T2 = 198°C
To find new volume V2, we would use Charles' law.
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles is given by;
[tex] VT = K[/tex]
[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]
Converting T1, from Celsius to Kelvin = 273 + 99 = 372K
Converting, T2, from Celsius to Kelvin = 273 + 198 = 471K
[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]
Making V2 as the subject formula, we have;
[tex] V_{2}= \frac{V1}{T1} * T_{2}[/tex]
[tex] V_{2}= \frac{1.03}{372} * 471[/tex]
[tex] V_{2}= 0.0028 * 471[/tex]
V2 = 1.32L
Therefore, the balloon will occupy a volume of 1.32L at 198°C
An aqueous solution is in equilibrium with a gaseous mixture containing an equal number of moles of helium, carbon dioxide, and nitrogen. Rank the relative concentrations of each gas in the aqueous solution from highest to lowest. An aqueous solution is in equilibrium with a gaseous mixture containing an equal number of moles of helium, carbon dioxide, and nitrogen. Rank the relative concentrations of each gas in the aqueous solution from highest to lowest.
[CO2][CO2] > [He][He] > [N2][N2] [N2][N2] > [CO2][CO2] > [He][He] [CO2][CO2] > [N2][N2] > [He][He] [He][He] > [N2][N2] > [CO2][CO2]
Answer:
[CO2] > [N2] > [He]
Explanation:
The relative concentration of CO2, N2 and He depends on the solubility of each gas in water. The more soluble in water a gas is, the greater its concentration in aqueous solution.
Among the gases listed, CO2 is most soluble in water hence it is expected to have the greatest concentration in solution followed by N2. Helium gas is insoluble in water hence it has the least concentration in the aqueous solution.
Lars observes a substance to be a solid and to float in water at room temperature (23°C). Based on the given properties, which substance is the most likely identity of this sample?
Substance Melting Point (°C) Boiling Point (°C) Density at Room Temperature (g/cm3)
carbon tetrachloride -22.9 76.7 1.59
cetyl alcohol 49.3 344 0.811
dichlorobenzene 53.5 174 1.25
sulfur hexafluoride -64 -50.8 0.00617
A.
carbon tetrachloride
B.
cetyl alcohol
C.
dichlorobenzene
D.
sulfur hexafluoride
Answer:D. Sulfur Hexafluride
Explanation:
D. Sulfur Hexafluride
Explanation:
above it says the substance floats above water at room temperature and lists some substances and their density at room temp!
we know that the density of water is 1.0 so the substance in order for it to float has to be less than 1.0 and the densities for Sulfer Hexa, are all less than 1!!
What are the possible consequences of adding a chemical to the environment
Answer:
The release into the air of chemicals and particles can cause direct damage to the troposphere (air pollution); alter the composition and function of atmospheric layers (greenhouse effect) or other indirect damages (ozone layer depletion).
Explanation:
What type of compound is iron(III) oxide?
Group A metal ionic compound with nonmetal anion
Group A metal ionic compound with polyatomic anion
transition metal ionic compound with polyatomic anion
transition metal ionic compound with nonmetal anion
Answer:transition metal ionic compound with nonmetal anion
Explanation:
Answer:
Your answer is going to be D. transition metal ionic compound with nonmetal anion
Hope this helps :)
Some Reactions are endothermic
How does the temperature and energy change in an endo thermic reaction?
temperature change
energy change
А
decreases
energy taken in
B
decreases
energy given out
С
increases
energy taken in
increases
energy given out
D
increases
energy given out
Answer:
endothermic means energy is taken in and temperature increases.
What is the difference in drawing Lewis Dot
Structures for ionic and covalent bonds?
The Lewis Dot Structure for ionic compounds must demonstrate how the electrons are transported to create the ions in the compound. The Lewis Dot Structures of covalent compounds must demonstrate how the electrons are being shared to finish the octets of each atom in the molecule.
What is an ionic compound ?A chemical compound known as an ionic compound is one that contains ions bound together by the electrostatic forces known as ionic bonding. Despite having both positively and negatively charged ions, or cations and anions, the molecule is generally neutral.
The term "ionic bonding" refers to a bond in which the ionic character is greater than the covalent character, i.e., when there is a significant difference in the electronegativity of the two atoms, which makes the bond more polar (ionic) than in a covalent bond, where the electrons are distributed more evenly.
The Lewis structures are not frequently drawn for ionic compounds due to the electrical motion of electrons.
Thus, The Lewis Dot Structure for ionic compounds must demonstrate how the electrons are transported to create the ions in the compound.
To learn more about an ionic compound, follow the link;
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5) A pure substance which can be decomposed by a chemical change is a
A) mixture
B) compound
C) metal
D) nonmetal
. If you apply heat to the copper bar, its density will
Answer:
Decrease
Explanation:
Density is defined as the mass per unit volume. Density is highly influenced by temperature.
The density of metals and copper is inversely proportional to the temperature, it means density of copper decreases with an increase in temperature or when heated. This is so because when the copper is heated, the copper atoms start vibrating faster that allows the collision of atoms with each other faster and occupying more volume than before. As the copper atoms occupy more volume, the density of copper decreases.
Hence, the correct answer is "On applying heat the density of copper decreases".
A student titrates 0.1719 g of an unknown monoprotic acid to the equivalence point with 21.85 mL of 0.1062 M NaOH. Which of the following is most likely to be the unknown acid? propionic acid (MM 74.08 g/mol) nitrous acid (MM 47.01 g/mol) chlorous acid (MM 68.46 g/mol) benzoic acid (MM 122.12 g/mol) lactic acid (MM: 90,08 gimol)
Answer:
Propionic acid
Explanation:
Step 1: Write the generic neutralization reaction
HA + NaOH ⇒ NaA + H₂O
Step 2: Calculate the reacting moles of NaOH
21.85 mL of 0.1062 M NaOH react.
0.02185 L × (0.1062 mol/L) = 2.320 × 10⁻³ mol
Step 3: Calculate the reacting moles of HA
The molar ratio of HA to NaOH is 1:1. The moles of HA are 1/1 × 2.320 × 10⁻³ mol = 2.320 × 10⁻³ mol.
Step 4: Calculate the molar mass of HA
0.1719 g of HA correspond to 2.320 × 10⁻³ moles.
MM = 0.1719 g/2.320 × 10⁻³ mol = 74.09 g/mol
With this molar mass, the most likely acid is propionic acid.