Answer:
Because the moon's path is predictable
Explanation:
The moon affects the tides
Gerald's science teacher mixed liquid X and liquid Y, both at room-temperature, in a large beaker. two beakers of clear solutions to the left of a right-pointed arrow, and a large beaker with a clear solution to the right of the arrow The mixture in the large beaker still looked clear like water, but when the students, one at a time, carefully touched the outside of the large beaker, it felt warm to the touch. Why did the large beaker most likely feel warm? A. The two liquids were not soluble in water. B. The release of a gas heated the solution. C. A chemical reaction produced a new substance. D. The energy of mixing warmed the liquids.
Answer:
c
Explanation:
A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
What is chemical reaction?chemical reaction, the transformation of one or more chemicals (the reactants) into one or more distinct compounds (the products). Chemical elements or chemical compounds make up substances.
A chemical reaction is one in which two or more reactants will react to form a new substance. When new substance will form it will produce heat. Therefore, when science teacher was mixing two liquids it was generating heat.
Heating a substance allow molecules to move faster. When heat is given to the object it will move fast. When heat will apply to a solid it will turn into liquid. When heat is supplied to the liquid it will turn into gas.
Therefore, A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
To learn more about chemical reaction, refer to the link:
https://brainly.com/question/22817140
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4.0 g of sodium hydroxide NaOH was dissolved in sufficient water to make up 125 mL of solution.
A) Find the concentration of the solution.
B) What mass of sodium hydroxide could be obtained by heating a 20 mL sample of this solution to dryness?
C) If 30 mL of the solution were mixed with sufficient water to produce 480 mL of a more dilute solution, what would be the concentration of the dilute solution?
D) If 200 mL of the more dilute solution were then mixed with 100 mL of the more concentrated solution, what would be the concentration of the mixed solution?
Answer:
(A) 0.80 M
(B) 0.64 g
(C) 0.050 M
(D) 1.6 M
Explanation:
(A)
Convert 4.0 g to moles with molar mass. Convert 125 mL to L.
4.0 g x (1 mol/39.998 g) = 0.100 mol
125 mL x (1 L/1000 mL) = 0.125 L
Molarity = mol/L
Molarity = 0.100 mol/0.125 L = 0.80 M
(B)
Find moles of NaOH with the molarity you just found. And convert 20 mL to L.
Molarity = mol/L
0.80 M = mol/0.020 L
mol = 0.016
Convert moles to grams with molar mass.
0.016 mol x (39.998 g/1 mol) = 0.64 g
(C)
You know the molarity of a NaOH solution (Part A). 30 mL initial volume and 480 mL final volume are given. Dilution question so use the dilution formula.
M1V1 = M2V2
(0.80 M)(30 mL) = (M2)(480 mL)
M2 = 0.050 M
(D)
Dilution question again, use the dilution formula.
M1V1 = M2V2
(0.80 M)(200 mL) = (M2)(100 mL)
M2 = 1.6 M
What is the mass of sulfuric acid, H2SO4, that is contained in 2.0 L of a 5.85 M solution ?
A-1147.44 grams
B- 0.12 grams
C-11.7 grams
D-98.07 grams
What is a chemical bond?
How many moles are in 12 liters of Cl2?
Answer:
[tex]\boxed {\boxed {\sf 0.54 \ mol \ Cl_2}}[/tex]
Explanation:
A mole is any quantity of a substance that contains 6.02 × 10²³ particles. At standard temperature and pressure, or STP, 1 mole of as is equal to 22.4 liters. This is true for any gas, regardless of the specific kind.
Although it is not specified, we can assume this gas is at STP. Let's set up a ratio using this information: 22.4 L/mol
[tex]\frac {22.4 \ L \ Cl_2}{1 \ mol \ Cl_2}[/tex]
Multiply by the given number of liters: 12
[tex]12 \ L \ Cl_2 *\frac {22.4 \ L \ Cl_2}{1 \ mol \ Cl_2}[/tex]
Flip the ratio so the liters of chlorine cancel.
[tex]12 \ L \ Cl_2 * \frac {1 \ mol \ Cl_2}{22.4 \ L \ Cl_2}[/tex]
[tex]12 * \frac {1 \ mol \ Cl_2}{22.4 }[/tex]
[tex]\frac {12}{22.4 } \ mol \ Cl_2[/tex]
[tex]0.53571428571 \ mol \ Cl_2[/tex]
The original measurement of liters has 2 significant figures, so our answer must have the same.
For the number we found, that is the hundredth place.
0.53571428571The 5 in the thousandth place tells us to round the 3 up to a 4.
[tex]0.54 \ mol \ Cl_2[/tex]
12 liters of chlorine gas at STP is approximately 0.54 moles of chlorine gas.
Which of the following pictures is a chemical change, and which is a
physical change? Explain in the boxes next to the picture.
Plz explain
Answer:
left is chemical because its chemicals, and right is physical because the ice cream is melting and thats physical
Explanation:
F or pass? I’m okay with pass
Answer:
pass
Explanation:
pass
N3- ion name pls help!!
Answer:
N with a charge of (-3) is nitride
Explanation:
A gaseous mixture contains 5.0 moles of nitrogen and 10.0 moles of helium . What is the total pressure if the temperature is 25 degrees C and the volume is 3.0 L? a) 122 atm
B) 56 atm
d) 2.0 atm
C)3.0 atm
Answer:
A) 122 atm
Explanation:
PV = nRT
Solve for P --> P = nRT/V
n = 10.0 mol + 5.0 mol = 15.0 mol
R = 0.08206 L atm / mol K
T = 25 + 273 = 298 K
V = 3.0
P = (15.0)(0.08206)(298) / (3.0) = 122 atm
how many grams is 4.2 moles HCL
Define the law of conservation of charge and provide an example.
Define opposite charges attract and like charges repel and provide an example.
Define Electricity along with an example.
Answer:
Conservation of Charge is the principle that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always conserved.
Why might changes to an environment cause an organism’s population to decrease?
PLZ HELP!
Are water waves transverse or longitudinal? How do you know? IN YOUR OWN WORDS.
Explanation:
Transverse waves are always characterized by particle motion being perpendicular to wave motion. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves.
Please help with ALL!
Answer:
A. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
B. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
C. Particle emitted = beta particles; protons gained = 1; Change in mass = 0
D. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
E. Particle emitted = gamma ray; protons gained = 0; Change in mass = 0
F. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
Explanation:
Radioactivity is the spontaneous disintegration of nucleus of an atom resulting in emission of particles and radiation unyil a stable atomic nuclei is obtained. Substances that are exhibit radioactivity are known as radioactive substances and are usually isotopes of stable atoms.
The types of radiation emitted by a radioactive substances include alpha rays, beta rays, and gamma rays.
Alpha rays or particles are fast moving positively charged particles with a mass number of four and atomic number of two. Thus, each alpha particle is a helium nucleus.
Beta rays or particles are vary fast moving stream of electrons having a mass number of zero and a charge of -1.
Gamma rays are not particles but are electromagnetic waves similar to visible light and X-rays but with shorter wavelengths. They have no mass or charge.
An atom emitting alpha particles has its mass reducing by 4 units and its atomic number decreasing by 2.
An atom emitting beta particles as it decays has no change in mass but its atomic number increases by 1.
From the table:
A. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
B. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
C. Particle emitted = beta particles; protons gained = 1; Change in mass = 0
D. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
E. Particle emitted = gamma ray; protons gained = 0; Change in mass = 0
F. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4
What effect could the pollution of Groundwater have on a nearby River, Lake or Stream?
Answer:
please give me brainlist and follow
Explanation:
Contamination of ground water can result in poor drinking water quality, loss of water supply, degraded surface water systems, high cleanup costs, high costs for alternative water supplies, and/or potential health problems. The consequences of contaminated ground water or degraded surface water are often serious.
What variable represents thermal energy in the equation Q = mcΔT?
A.
The variable c
B.
The variable Q
C.
The variable T
D.
The variable m
Answer:
The variable Q
Explanation:
i just took the test and got it right.... i hope this helps :)
The variable Q represents thermal energy in the equation Q = mcΔT. Hence, option B is correct.
What is specific heat capacity?The specific heat capacity is defined as the quantity of heat (J) absorbed per unit mass (kg) of the material when its temperature increases by 1 K (or 1 °C), and its units are J/(kg K) or J/(kg °C).
Q = mcΔT
Q = heat energy
m = mass
c = specific heat capacity
ΔT = change in temperature
Hence, option B is correct.
Learn more about specific heat capacity here:
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Consider the following balanced equation:
2KCIO3(s) → 2KCl(s) + 302(g)
How many moles of O2 will be obtained by decomposing
3.50 moles of KCIO3?
0.530 mole
O 3.00 moles
O 2.30 moles
5.25 moles
5.25 moles
General Formulas and Concepts:Chemistry
Atomic Structure
CompoundsMolesAqueous Solutions
States of matterStoichiometry
Analyzing reactions RxNUsing Dimensional AnalysisExplanation:Step 1: Define
[RxN - Balanced] 2KClO₃ (s) → 2KCl (s) + 3O₂ (g)
[Given] 3.50 mol KClO₃
[Solve] mol O₂
Step 2: Identify Conversions
[RxN] 2 mol KClO₃ (s) → 3 mol O₂ (g)
Step 3: Stoichiometry
[DA] Set up conversion: [tex]\displaystyle 3.50 \ mol \ KClO_3(\frac{3 \ mol \ O_2}{2 \ mol \ KClO_3})[/tex][DA} Multiply [Cancel out units]: [tex]\displaystyle 5.25 \ mol \ O_2[/tex]how many ml of 12.0 m hcl are needed to prepare 1200 ml of a 0.10 M solution of hcl
This means that if you know how many moles of solute you have in the target solution, you also know how many moles of solute were present in the stock solution sample.
Use the molarity and volume of the target solution to determine how many moles of hydrochloric acid,
HCl
, you need in that solution
c
=
n
V
⇒
n
=
c
⋅
V
n
HCl
=
0.10 M
⋅
500
⋅
10
−
3
L
=
0.050 moles HCl
Now the question is - what volume of stock solution would contain this many moles of hydrochloric acid?
c
=
n
V
⇒
V
=
n
c
V
stock
=
0.050
moles
12
moles
L
=
0.0041667 L
I'll leave the answer rounded to two sig figs, despite the fact that you only gave one sig fig for the volume of the target solution
V
stock
=
4.2 mL.follow me
Use the food web below to answer the following
question.
Frog
Red fox
Grasshopper
Weasel
Goldfinch
Great horned om
Clover
Deer mouse
Which group is not represerted in the food web?
A. producers
B. primary consumers
C. secondary consumers
D. decomposers
Answer:
uhm i believe its D hope i helped
Explanation:
Answer:
D. decomposers
Calculate the mass of iron which will be converted into its
oxide (Fe3O4) by the action of 20 grams of steam on it.
3Fe + 4H2O + Fe3O4 + 4H2
Answer: 46.66 Grams
Explanation:
Credits to jasminealexismacias, Enjoy your CK12
Se mezclan 20 gramos de agua (1cal/g°C) a 40 °C con 15 gramos de alcohol (0,58cal/g°C) a 30 °C. ¿Cuál ha sido la temperatura de equilibrio térmico?
Answer:
[tex]T_{EQ}=37\°C[/tex]
Explanation:
¡Hola!
En este caso, para los problemas de equilibrio térmico, consideramos que la energía liberada por la sustancia que inicialmente está caliente (agua), es absorbida por la sustancia que inicialmente está fría (alcohol); thus, we can write:
[tex]Q_{agua}=-Q_{alcohol}[/tex]
La cual puede ser escrita en términos de masa, calor specifico y temperaturas:
[tex]m_{agua}C_{agua}(T_{EQ}-T_{agua})=-m_{alcohol}C_{alcohol}(T_{EQ}-T_{alcohol})[/tex]
De este modo, al resolver para la temperature de equilibrio térmico, obtenemos la siguiente expresión:
[tex]T_{EQ}=\frac{m_{agua}C_{agua}T_{agua}+m_{alcohol}C_{alcohol}T_{alcohol}}{m_{agua}C_{agua}+m_{alcohol}C_{alcohol}}[/tex]
Así, al reemplazar los valores en esta, obtenemos:
[tex]T_{EQ}=\frac{(20g)(1cal/g\°C)(40\°C)+(15g)(0.58cal/g\°C)(30\°C)}{(20g)*(1cal/g\°C)+(15g)(0.58cal/g\°C)} \\\\T_{EQ}=37\°C[/tex]
¡Saludos!
What is the mass of 925.4 L of hydrogen gas at STP?
Answer:
If this is an idea gas then 1mol takes up 22.4L.
So, knowing how many L you have you can figure out how many mole syou have by doing a simple equation:
[tex]\frac{1mol}{y} =\frac{22.4L}{925.4L}[/tex]
Solve for y.
Then, since you know how many moles you have use the ptable https://ptable.com/#Properties to figure out the mass in grams.
NOTE: The ptable tells you that 1mol of H = 1g.....so this should be an easy calculation :) enjoy
Reactants of a combustion reaction include
select all that apply
Fuel
Oxygen
Water
Carbon Dioxide
Answer: fuel and oxygen are reactants.
Explanation:
Answer:
fuel and oxygen
Explanation:
I take test
5 The atoms of a certain element each contain 36 protons and 8 valence electrons. Which
statement correctly identifies this element and describes its chemical reactivity? (8.58)
A The element is krypton, Kr, and it is not very reactive.
B The element is chlorine, Cl, and it is highly reactive.
C The element is krypton, Kr, and it is highly reactive.
D The element is chlorine, Cl, and it is not very reactive.
Answer:
dfdfaxc b
Explanation:
9. What happens to the cell outside of the nucleus when the virus has been copied so many times? a. The cell fights back b. The cell gets help from its neighbor cells C. The cell gets help from white blood cells d. The cell is destroyed
Answer: it think the answer is c.) The cell gets help from white blood cells or b.) The cell gets help from its neighbor cells.
Explanation:
A buffer is made with 0.493 M of the weak base methylamine ([tex]CH3NH2[/tex]) with 0.493 M [tex]CH3NH3Cl[/tex] (KA = 5.6 x 10^-4)
What is the pH of this buffer system?
If 0.100 M HBr is added to the buffer, what is the pH?
h^ ar hidrojen oksijen azot helyum
Which of the following is a FALSE statement? *
A. Heat moves through solids by by conduction.
B. Molecules move faster in warmer substances.
C. Warm water is denser than cold water.
D. Heat moves through liquids and gases by convection.
Answer:
C: Warm water is denser than cold water
Please help I'm not sure what the answers are
Answer:
An element's mass number (A) is the sum of the number of protons and the number of neutrons. The small contribution of mass from electrons is disregarded in calculating the mass number.
Plutonium is a radioactive material, exposure to which is hazardous to human health, and is one of the few materials that can be used to make a nuclear weapon. The time it takes for half of any initial quantity of plutonium to decay into stable non-radioactive products is roughly:
Answer:
24,000 years
Explanation:
Which of the following statement is not true?
Answer: 2
Explanation: Greenhouse gases are very important in keeping our planet just right. If we have too many Greenhouse gases it would be too hot, but we can't eliminate all of them or it will be too cold
