Answer:
Coal is made from plants that were once alive! Since coal comes from plants, and plants get their energy from the sun, the energy in coal also came from the sun
A large pile of marbles weigh 592.45g. 15 marbles weigh 43.35 g. How
many marbles are in the large pile
Answer:
205 marbles.
Explanation:
Hello there!
In this case, according to the given information in this problem, it is possible for us to realize that the weight of 15 marbles is 43.35 g and the idea is to calculate the number of marbles in 592.45 g, so we can use the following setup:
[tex]\frac{15marbles}{43.35g} =\frac{x}{592.45g}[/tex]
And we solve for x as follows:
[tex]x=\frac{15marbles*592.45g}{43.35g} \\\\x=205marbles[/tex]
Regards!
What is the pH of 0.0000043M HNO3 ? (3 sig figs, round the last digit only if needed)
Answer:
pH = 5.37
Explanation:
We'll begin by obtaining the concentration of the hydrogen ion in the solution. This can be obtained as follow:
HNO₃ (aq) —> H⁺ (aq) + NO₃¯ (aq)
From the balanced equation above,
1 mole of HNO₃ produced 1 mole of H⁺.
Therefore, 4.3×10¯⁶ M HNO₃ will also produce 4.3×10¯⁶ M H⁺.
Finally, we shall determine the pH of the solution. This can be obtained as follow:
Concentration of Hydrogen ion [H⁺] = 4.3×10¯⁶ M
pH =?
pH = –Log [H⁺]
pH = –Log 4.3×10¯⁶
pH = 5.37
Therefore, the pH of the solution is 5.37
How many moles of solute are in 250 mL of 2.0 M CaCl ?
Answer:
[tex]\boxed {\boxed {\sf 0.5 \ mol \ CaCl}}}[/tex]
Explanation:
Molarity is a measure of concentration in moles per liter.
[tex]molarity= \frac{moles \ of \ solute}{liters \ of \ solution}[/tex]
We know the molarity is 2.0 M CaCl. However, we can convert the units to make the problem easier. 1 molar (M) is equal to 1 mole per liter. A 2.0 M CaCl molarity is equal to 2.0 moles of CaCl per liter.
We also know there are 250 milliliters of solution. however, we need to find the liters. Remember that 1 liter contains 1000 milliliters.
[tex]\frac { 1 \ L}{1000 \ ml}[/tex][tex]250 \ mL * \frac { 1 \ L}{1000 \ ml}[/tex][tex]250 * \frac { 1 \ L}{1000}= 0.250 \ L[/tex]Now we can substitute the values we know into the formula. Since moles of solute are unknown, we can use x.
molarity= 2.0 mol CaCl/ L moles of solute =x liters of solution = 0.250 L[tex]2.0 \ mol \ CaCl/ L= \frac{x}{0.250 \ L}[/tex]
Since we are solving for x (the moles of solute), we need to isolate the variable. It is being divided by 0.250 L. The inverse of division is multiplication, so we multiply both sides by 0.250 L.
[tex]0.250 \ L *2.0 \ mol \ CaCl/ L= \frac{x}{0.250 \ L} * 0.250 \ L[/tex]
[tex]0.250 \ L *2.0 \ mol \ CaCl/ L=x[/tex]
The units of liters (L) cancel.
[tex]0.250 * 2.0 \ mol \ CaCl=x[/tex]
[tex]0.5 \ mol \ CaCl=x[/tex]
There are 0.5 moles of solute in 250 milliliters of a 2.0 M solution.
Study the model. The model shows a sodium chloride compound. What kind of substance is shown here? Select one: An atom. A molecule. An element. An extended structure.
Answer:
an element
Explanation:
it said compound and a compound is element.
Whilst Et₃CCl is unreactive towards water even at elevated temperatures, Et₃SiCl is hydrolyzed rapidly. Explain the origin of these differences and provide a reaction scheme with mechanistic details for the hydrolysis of Et₃SiCl.
Answer:
See Explanation
Explanation:
In discussing the reason why Et₃SiCl is more easily hydrolysed than Et₃CCl, we must remember that the electronegativity difference between silicon and chlorine is much higher than the electronegativity difference between carbon and chlorine.
As a result of this, the Si-Cl bond in Et₃SiCl is more polar and hence susceptible to attack by water than the C-Cl bond in Et₃CCl.
Also, it is postulated that the presence of vacant d orbitals on silicon assists hydrolysis in Et₃SiCl. Such vacant orbitals are absent in carbon hence Et₃CCl does not undergo hydrolysis.
The reaction scheme is shown in the image attached to this answer.
when a tip of a plant is cut it doesn't grow well
Explanation:
the tip of a growing plant contains special rapidly diving cells called apical meristem ,these cells are responsible for increase in the length of the plant . if we cut out these cells ,length growth of the plant will be stunned as these cells are not present anyplace else.
Which of the following has a mass of 10.0 g?
a 2.02 mol Ne
b 0.119 mol Kr
C 1.25 mol He
d 0.400 mol Ar
Answer:
the argon because 40/4 = 10
A sample of river wayer contains 125mg per dm^3 of dissolved soilds. Calculate the mass of dissolved soilds in grams in 250 cm^3 of this sample of river water. Giver your answer to 2 significant figures (4 marks)
I will give brainilist to anyone who answers
The mass of a substance is the product of its density and volume. Thus, the mass of the dissolved solids with a density of 125 mg/dm³ with a volume of 250 cm³ is 31.25 mg.
What is density?Density of a substance is the measure of its mass per unit volume. Thus it describes how much denser the substance is in a given volume. Mathematically it is the ratio of mass to the volume.
Density of a substance depends on the mass, volume, bond type, temperature and pressure. The ratio of density of a substance with the density of water is called its specific gravity.
It is given that the density of the dissolved solids is 125 mg/dm³ and the volume is 250 cm³ or 0.25 dm³. Thus the mass can be calculated as follows:
density = mass/volume
mass = density × volume
= 0.25 dm³ × 125 mg/dm³
= 31.25 mg
Hence, the mass of the dissolved solids in the river wayer is 31.25 M=mg.
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Help balance (will mark brainliest)
What will the volume be of a soltuion created using 120 ml of 4.5 M stock solution if the final molarity needs to be 2.00 M
Answer:
We need 540 mmoles of stock solution and complete to 270 mL of volume.
Explanation:
In order to determine the volume or concentration at diluted solution we apply this formula:
Dil volume . Dil concentration = Conc volume . Conc concentration
Stock solution is always, the concentrated.
Let's replace with data given:
Dil. volume . 2 M = 120 mL . 4.5 M
Diluted volume = (120 mL . 4.5M) / 2M
Diluted volume = 270 mL
This problem can be also solved by rule of three:
1 mL of stock solution contains 4.5 mmoles
120 mL of stock solution contain (120 mL . 4.5 mmoles) / 1mL = 540 mmoles
This mmoles of stock solution are also contained at the diluted
If 2 mmoles are contained in 1mL of diluted solution
540 mmoles must be contained in (540 mmol . 1 mL) / 2 mmol = 270 mL
We need 540 mmoles of stock solution and complete to 270 mL of volume.
18. How many grams are in 563 mL of chlorine gas at STP?
Answer:
[tex]at \: stp : \\ 22400 \: ml \: are \: occupied \: by \: 71 \: g \: of \: chlorine \\ 563 \: ml \: will \: be \: occupied \: by \: ( \frac{563}{22400} \times 71) \:g \\ = 1.78 \: g[/tex]
Hep balance equation
Answer:
4, 3, 1, 12
It balances now
How many atoms are there in 20.00 moles of calcium (Ca)?
Answer:
20 x (6.022 x 10^23) atoms in 20 moles of Calcium.
Explanation:
A mole contains 6.022 x 10^23 atoms, which is also known as Avogadro's number, and this number is same for each element. So, there are 20 x (6.022 x 10^23) atoms in 20 moles of Calcium.
The number of atoms are there in 20 moles of calcium is 120.4 × 10²³.
What is Avogadro's number?Avogadro's number is the number which is equal to the number of atoms of any substance that are present in one mole of that substance, and it is equal to 6.022 × 10²³.
Given moles of calcium = 20 moles
So, number of atoms in given moles of calcium will be calculated as:
No. of Ca in 20 mol = 20mol × 6.022 × 10²³ atoms/mol = 120.4 × 10²³ atoms
Hence required atoms of calcium is 120.4 × 10²³.
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Al aumentar la temperatura ¿Cómo varía la presión?
Answer:
california y nueva york
Explanation:
Answer:
las partículas se mueven más rápido, y por lo tanto tienen mayor velocidad, por lo tanto mayor impulso y por lo tanto mayor fuerza cuando chocan con las paredes, por lo que la presión aumenta.
Explanation:
20 mL of hydrogen measured at 15° C is heated to 35°C.
What is the new volume at the same pressure?
V2 = 21.4 ml
Explanation:
Note: When dealing with gases, make sure that you change the units from °C to K.
T1 = 15°C + 273 = 288K
T2 = 35°C + 273 = 308K
V1 = 20 ml
V2 = ?
We use Charles's law to solve V2:
V1/T1 = V2/T2
or
V2 = (T2/T1)V1
= (308K/288K)(20 ml)
= 21.4 ml
I WILL GIVE BRAINLIEST PLEASE ANSWER
Answer:
b. 1...1...1
Explanation:
Calculate the mass of NaOH
required to prepare a 0.343M
solution dissolved in 2500mL
of water.
Answer:
will this work or help?
Explanation:
Calculate the mass of NaOH required to prepare a 0.343 M solution dissolved in 2500 mL of water. 0.343 M = x mol / 2.5 L = 0.86 mol 0.86.
what is non polar covalent bond
Answer:
It is formed between two atoms of the same elements having same electronegativity in which the bonding electrons are equally shared between them. In this case, the centre of the positive charge coincides with the centre of the negative charge in theecular molecule. H, N: 0. etc. are the molecules in which non polar covalent bonds invalved. These substances are called non polar substances.
Answer:
A nonpolar covalent bond is a covalent bond in which the bonding electrons are shared equally between the two atoms. In a nonpolar covalent bond, the distribution of electrical charge is balanced between the two atoms.
Explanation:
The symbols for elements with atomic numbers 4, 9, 16, & 17 are? (Respectively)
Answer:
the answer is 4=Be 9 =F 16=S 17 = CL
Explanation:
atomic no 4 = beryllium (Be)
" " 9 = fluorine (F)
16 = sulfur (S)
17 = chlorine (CL)
The atomic number of Beryllium is 4, the atomic number of fluorine is 9, atomic number of sulfur is 16 and the atomic number of chlorine is 17.
What is atomic number?The atomic number is defined as the number of protons in the nucleus of an atom or the number of electrons revolving around the nucleus in orbits or shell.
So we can conclude that he atomic number of Beryllium is 4, the atomic number of fluorine is 9, atomic number of sulfur is 16 and the atomic number of chlorine is 17.
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Describe Covalent bond.
Answer:
The bond formed between 2 or more elements by sharing of electrons is called covalent bond
for ex, let's say Carbon, element of group 14 , it requires 4 electrons to complete it's octate it's valency is 4, now either it can donate 4 electrons to some other element or gain from others. but in both case it requires too much energy so, it neither loose the electrons nor gain, it shares its 4 electrons and formed a constant bond ex - ccl4, ch4 Bond formed by sharing of electron - covalent bond bond formed by gaining or loosing of electron is ionic bond.CAN SOMEONE PLEASE HELP
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Answer:
5.1 x 10^-3 M
Explanation:
Find number of moles of KOH used
.050 M /L * .017 L = .00085 moles of KOH
from the reaction equation, this will react with 1/2 as many moles of Ca 2+
or .000425 moles of Ca <===== in .084 Liter of water
.000425 moles / .084 liter = .00505 M =~ 5.1 x 10^-3 M
True or false: SOLIDS have a definite shape, a definite volume, and cannot flow.
This statement is true.
Answer:
true
Explanation:
because solids have strong intermolecular force of attraction so they have definite shape and volume and cannot flow
What is Potential energy
Answer:
energy that's waiting to happen
Explanation:
as an example if you throw a ball up in the air potential energy is going to happen when it comes down that's going to be energy basically I don't know if you get it but it's called potential energy
Answer:
Potential energy is the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.
Explanation:
A 10.0 cm by 4.00 cm pool is filled with water to a depth of 2.50 cm. How many joules are needed to heat the water from 18.5oC to 32.0oC? Cp of water = 4.184 J/goC
Answer:
5648.4 Joules
Explanation:
This problem can be solved by the calorimetry formula:
Q = C . m . ΔT
where ΔT indicates the change of temperature
Final T° - Initial T°
m = mass
C = specific heat of water and Q = Heat
We do not have m, but we have the volume of water. We can obtain mass from density.
Volume of water = 10 cm . 4cm . 2.50 cm = 100 cm³
1 cm³ = 1 mL
Density of water = 1 g/mL
Therefore our 100 mL of water is the volume for 100 g. We replace data:
Q = 4.184 J/g°C . 100 g . (32°C - 18.5°C)
Q = 5648.4 Joules
WILL MARK BRAINLIEST!!!!
How many moles are there in 993.6 grams of potassium sulfate (K2SO4)?
Answer:
5.702 mol K₂SO₄
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableCompoundsMolesStoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 993.6 g K₂SO₄
[Solve] moles K₂SO₄
Step 2: Identify Conversions
[PT] Molar Mass of K: 39.10 g/mol
[PT] Molar Mass of S: 32.07 g/mol
[PT] Molar mass of O: 16.00 g/mol
Molar Mass of K₂SO₄: 2(39.10) + 32.07 + 4(16.00) = 174.27 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 993.6 \ g \ K_2SO_4(\frac{1 \ mol \ K_2SO_4}{174.27 \ g \ K_2SO_4})[/tex][DA] Divide [Cancel out units]: [tex]\displaystyle 5.7015 \ mol \ K_2SO_4[/tex]Step 4: Check
Follow sig fig rules and round. We are given 4 sig figs.
5.7015 mol K₂SO₄ ≈ 5.702 mol K₂SO₄
3. (05.02 MC)
What is the mass of a sample of NH3 containing 3.80 x 1024 molecules of NH3? (5 points)
74.8 grams
89.4 grams
101 grams
107 grams
Answer:
107 g
Explanation:
need to divide by avogadro’s number
The mass of a substance is a weight that can be given by the moles. In the sample 107.27 gms of ammonia is present. Thus, option D is correct.
What is mass?Mass or the weight of the substance can be given by the molar mass and the moles of the substance.
We know,
6.02214076 × 10²³ molecules = 1 mole of NH₃
So, 3.80 x 10²⁴ molecules = 6.31 moles
If 1 mole = 17 gm ammonia
Then, 6.31 moles = 6.31 × 17 = 107 gms
Therefore, option D. 107 gms is the mass of ammonia.
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Please help this will determine my grade so I beg help me out and my grade
Answer:
C: checking your email
Explanation:
I believe that C would be impossible, as you cannot use wireless networks without radio waves
I’m brain dead, anyone know this shi
Answer:
Option 1
Explanation:
p can hold upto 6 e-.
It would be easy if it gains 2e-, instead of losing 4e-, to be stable.
It gains 2e, and gets a charge of - 2e.
It forms O (2-)
6.
An element with high conductivity would be found in which
category?
Alkaline earth metals
transition metals
Group 1 metal
Alkali metals
***Why would you not pick the others?
The diagram shows genetic structures.
Which label best represents the area marked Y?
chromosome
protein
gene
DNA
Answer:
The correct answer is - DNA (check image).
Explanation:
In this diagram, The W mark is the nucleus of the cell X is the chromosome Y represents the DNA and Z is the gene. Gene is the segment of the DNA and DNA is the pat of the chromosome with histone. Chromosomes are present in the nucleus of the cell. These all are the structures of the genetic structures.
Thus, the correct answer is - DNA.
Answer:
dna
Explanation:
edge