A catalyst used in a reaction remains unchanged
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.
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.
Learn more about atom here: https://brainly.com/question/6258301#SPJ2
Hep balance equation
Answer:
4, 3, 1, 12
It balances now
__________________ are high-speed bands of winds occurring at the top of the tropsophere.
Your answer:
Doldrums
Horse Latitudes
Jet Streams
Trade Winds
Answer:
jet streams
Explanation:
THE JET STREAM Narrow bands of exceedingly high speed winds are known to exist in the higher levels of the atmosphere at altitudes ranging from 20,000 to 40,000 feet or more. They are known as jet streams.
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.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.
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
What can the rock layers tell us about life on Earth?
Explanation:
The location of fossils in rock layers provides evidence of Earth's past landscapes. ... Scientists use a technique called radiocarbon dating to find out the age of the fossils. Once they know the age of the fossil in the rock, they also know that rock itself is about the same age!
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.
To find more on density, refer here:
https://brainly.com/question/15164682
#SPJ2
How is coal extracted?
How do Humans use it?
What are the benefits?
Coal is extracted by mining.
Once coal has been extracted, it can be used directly for heating and industrial processes or to fuel power plants for electricity.
Benefits are:
Coal energy is an affordable energy source because of the coal's stable price compared to other fuel sources.
Coal is easy to burn.
Coal produces high energy upon combustion.
Coal energy is inexpensive.
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
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.
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-)
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:
can somebody help me with this.
Answer:
HI
H₂O
H₃O⁺
I⁻
Explanation:
Bronsted-Lowry acids are chemicals that can donate protons, and Bronsted-Lowry bases are chemicals that can accept them. Conjugate bases and acids are the resulting effect of losing or gaining a proton in the form of H⁺.
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
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 1.0 M KOH solution?
Answer:
pH = 14
Explanation:
pOH = -log[OH-] = -log1,0 = 0
pH + pOH = 14
pH = 14 - pOH = 14 - 0 = 14
Answer:
pH= 14Explanation:
hope it helps
#CARRYONLEARNING20 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
You have a block of wood with a mass of 700 grams and a volume of 1100 cm.
What is the density of wood?
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:
A solution with a pOH of 4.3 has a [H+] of ??
please help
Answer:
A solution with a pOH of 4.3 has a [H+] of 2*10⁻¹⁰ M.
Explanation:
The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution.
pOH indicates the concentration of hydroxyl ions [OH-] present in a solution. It is defined as the negative logarithm of the activity of hydroxide ions. That is, the concentration of OH- ions:
pOH= -log [OH-]
On the other hand, pH is also a measure of the basicity or alkalinity of a solution. POH is an indicator that is related to pH by:
pOH + pH= 14
So, if the solution has a pOH equal to 4.3, the pH is calculated by:
4.3 + pH= 14
pH= 14 - 4.3
pH= 9.7
The pH is defined as the logarithm of the concentration of H+ ions, with the sign changed:
pH= -log [H+]
So, in this case:
9.7= - log[H+]
Solving
[H+]= 2*10⁻¹⁰ M
A solution with a pOH of 4.3 has a [H+] of 2*10⁻¹⁰ M.
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?
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]
(b) Two containers made of Insulating material contain the same volume of water at roorh
temperature. The containers do not have lids. The volume of liquid in each container graduall- decreases.
(i) After a certain time, the temperature of the water has decreased to below room
temperature.
Explain, in terms of molecules, why the temperature has decreased.
(ii) One of the containers is wide and shallow. The other container is narrow and deep.
Predict which container has the greater rate of cooling. Explain your answer.
Answer:
See Explanation
Explanation:
Evaporation is an endothermic process, an endothermic process is one in which energy is absorbed from the surrounding thereby making the system to be at a lower temperature compared to the environment.
Being an exothermic process, molecules take away energy from the liquid surface as they escape from the liquid surface hence, evaporation causes the temperature of the water to be decreased below room temperature.
The rate of evaporation and cooling depends on the surface area of liquid. The liquid in the wide and shallow container has a greater rate of cooling because it has a greater surface area than the liquid in the narrow and deep container.
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
For which substance is the standard heat of formation not equal to zero?
Hydrogen (H2)
Aluminum oxide (Al2O3)
Oxygen (O2)
Potassium (K)
Answer:
Aluminum oxide (Al₂O₃)
Explanation:
The standard heat (or enthalpy) of formation of a compound, is the amount of change in the enthalpy that takes place when 1 mole of the compound is produced from the elements it contains whereby the compounds and elements in the reaction are in their standard states
The standard state of an element, is the state in which the element is in the most stable form at a pressure of 1 bar
Therefore, the heat of formation of hydrogen, H₂, oxygen, O₂, and potassium, (K), will have a heat of formation of zero, while Al₂O₃ which is made of aluminum and oxygen in combining to form a compound in proportions which are different from their initial standard states will have a heat of formation not equal to zero
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
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
The potential energy diagram for a reaction starts at 180 kJ and ends at 300 kJ. What type of reaction does the diagram best represent? (5 points)
Exothermic reaction
Endothermic reaction
Reaction between two solids
Reaction between two liquids
Answer:
Exothermic reaction
Explanation:
An exothermic process releases heat, causing the temperature of the immediate surroundings to rise
The potential energy diagram for a reaction starts at 180 kJ and ends at 300 kJ. the type of reaction does the diagram best represent exothermic reaction.
What is exothermic reaction?An exothermic reaction would be one in which heat energy is emitted. Exo stands for "evolve out." The term "thermos" refers to a container that holds heat. The term "exothermic" refers to a process in which heat is produced. In general, an exothermic reaction is one in which heat is released as a byproduct.
Therefore, the reaction diagram will represent exothermic reaction.
To know more about exothermic reaction.
https://brainly.com/question/10373907.
#SPJ2