From the formula of methane it is clear that one mole of methane has 4hydrogen atoms. So, 37.6×1023 hydrogen atoms are there in 25.0 g of methane. Therefore, 9.4×1023methane molecules and 9.4×1023 hydrogen and 37.6×1023carbon atoms are there in 25.0 g of methane.
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Based on the enthalpy changes given for the reactions, which reactions are endothermic?
Explanation:
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Who made the first periodic table of the elements?
O A. Ernest Rutherford
O B. Dmitri Mendeleev
O C. Niels Bohr
O D. Henry Moseley
The periodic table was invented by Russian chemist Dmitri Mendeleev in 1869.
Answer:
B. Dmitri Mendeleev
Explanation:
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process name of liquid bromine to bromine vapor
Answer:
evaporation, vaporisation, boiling if change occurs at boiling point
Explanation:
What is the gram molecular mass of a compound if 5 moles of the compouns has a mass of 100 grams?
Answer:
20 grams.
Explanation:
5 mols of a compound has a mass of 100 grams
1 mol of the same compound has a mass of 100/5 = 20 grams
The part of an atom that has an overall positive charge is called
A)
an electron
B)
the nucleus
C)
the first shell
D)
the valence shell
Answer: I think it’s B
Geef de systematische namen van SiF2
The question is: Give the systematic name of [tex]SiF_{2}[/tex].
Answer: The systematic name of [tex]SiF_{2}[/tex] is silicon difluoride.
Explanation:
The given compound has chemical formula [tex]SiF_{2}[/tex]. It shows that there is one atom of silicon and two atoms of fluorine are present.
So, the number "two" will be represented by the prefix "di" while naming this compound.
Hence, systematic name of this compound is silicon difluoride.
Thus, we can conclude that systematic name of [tex]SiF_{2}[/tex] is silicon difluoride.
How many grams of Al will be deposited from molten AlCl3 by a current of 15.0 amp flowing for 24.0 hr ( 1 Faraday = 96500 C)
0.538 g
0.0335 g
363 g
121 g
Answer:
121 aprox.
Explanation:
mass/molar mass = Q/CF
where mass=?
molar mass of Al=27
Q=It = 15×24×60×60
C=3
F=96500
Which functional group defines an alcohol?
0 – PO4
O =
= 0
o
– Na
o
- ОН
Explain why rubbing an alkali like bicarbonate of soda onto an acidic bee sting can ease the pain ?
does salt affect the boiling time of water?
Answer:
Yes
Explanation:
Yes, but almost insignificantly. The regular boiling point of water is 100 degrees celcius, adding a small handfull of salt will increase the boiling point to roughly 100.04 degrees celcius. Therefore, it is almost insignificant but still does affect it. This is mainly because salt changes the way the molecules react thus making it harder for them to change state from liquid to gas. This ultimately causes the water to get hotter before boiling actually occurs.
Why increasing the temperature of a gas would increase the volume of its container in gas law?
When the amount of gas in a container is increased, the volume increases. Lussac's law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature.
a sample of silver has a volume of 6 cm^3 and a massage of 36 grams what's the samples density
Answer:
6g/cm³
Explanation:
Density of a substance can be calculated as follows:
Density = mass (g)/volume (cm³)
According to this question, a sample of silver has a volume of 6 cm³ and a mass of of 36g. The density will be
Density = 36/6
Density = 6g/cm³
¿Cuál de los siguientes valores es igual a 1 micrómetro?
O 0,000001 metro
O 0,001 metros
O 1.000 metros
O 1.000.000 metros
The melting and boiling points of table salt and table sugar are given below.
Why does table salt have much higher melting and boiling point than table sugar?
o A strong ion -ion attractions in table salt
O B. weak ion-ion attractions in table sugar
O C. strong ion-ion attractions in table sugar
O
D. weak ion-ion attractions in table salt
Answer:
weak ion attractions in the table salt
A neutron collides with a nitrogen atom, resulting in a transmutation. Balance the equation.
on + '
NX+1H
Identify the unknown product by identifying the unknown letters.
Ais
Z is
X is
Answer:
The answer is ¹³₆C
Explanation:
searched it up
A3B8 + C2 ---> AC2 +
B2C
1. What is the balanced equation for the combustion reaction?
Answer:
A₃B₈ + 5C₂ –> 3AC₂ + 4B₂C
Explanation:
A₃B₈ + C₂ –> AC₂ + B₂C
The equation can be balance as illustrated below:
A₃B₈ + C₂ –> AC₂ + B₂C
There are 3 atoms of A on the left side and 1 atom on the right side. It can be balance by writing 3 before AC₂ as shown below:
A₃B₈ + C₂ –> 3AC₂ + B₂C
There are 8 atoms of B on the left side and 2 atoms on the right side. It can be balance by writing 4 before B₂C as shown below:
A₃B₈ + C₂ –> 3AC₂ + 4B₂C
There are 2 atoms of C on the left side and a total of 10 atoms on the right side. It can be balance by writing 5 before C₂ as shown below:
A₃B₈ + 5C₂ –> 3AC₂ + 4B₂C
Now, the equation is balanced.
23. What type of chemical reaction is: CH, + 0→ CO2 + H20
a. Combustion
b. Neutralization
C. Synthesis
d. Double Replacement
Answer:
combustion
Explanation:
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Radhika loves to eat sweets and chocolates. She asks her mother for the same before and after every meal. Explain if this is an example of bad eating habit or healthy eating habit?
Answer: Radhika loves to eat sweets and chocolates. She asks her mother for the same before and after every meal. This is an example of bad eating habit.
Explanation:
Both sweets and chocolates contain high amount of fat and sugar. When Radhika is eating the same before and after every meal then it means she is consuming it in excess.
When we eat too much of sweets and chocolates then its remains get deposited in between our tooth and when they remain over there for hours then more amount of bacteria is formed.
Due to this bacteria our tooth starts to decay.
Hence, it is advised even by the doctors to eat sweets and chocolates occasionally and not regularly.
Thus, we can conclude that Radhika loves to eat sweets and chocolates. She asks her mother for the same before and after every meal. This is an example of bad eating habit.
Which greenhouse gas is produced when fossil fuels are burned for energy?
A. Petroleum
B. Methylamine
C. Helium
D. Carbon dioxide
Answer:
D. Carbon Dioxide
What has the most direct cause to the increase in the number and ferocity (strength) of storms hitting the Caribbean and the United States in recent years?
Answer:
High amount of humidity
Explanation:
This is especially common in the Caribbean, where hot temperatures very moisture and warm air provide near-ideal circumstances for hurricane formation, as assessed by the Saffir-Simpson classification and the Power Distribution Index.
"Hurricanes may originate everywhere in the Atlantic basin, from the subtropical central Atlantic to the Gulf coast. However, in order to make this all the way to the West Coast of the United States, the storms must pass over a lengthy length of sea water which is far too small to support hurricanes.
The storm strength is influenced by a lot of factors. Due to world warms and increase in the amount of humidity.
What is causing the increase in storm strength?
Studies has shown due too the warming of the world, hurricanes and other tropical cyclones are said to be more stronger.
This is due to the fact that warmer water gives more of the energy that boast storms. A rise in stronger hurricanes is due to warming never ending.
Learn more about storm strength from
https://brainly.com/question/25775340
What is the molarity if 60.4 grams of hydrochloric acid was added to 505 mL of water?
M
H - 1.0079 g/mol
Cl- 35.453 g/mol
Answer:
3.29 M
Explanation:
Molarity refers to the molar concentration of a solution and it can be calculated using the formula below:
Molarity (M) = number of moles (n) ÷ volume (V)
According to this question, the mass of HCl was given to be 60.4 grams and the volume of water as 505 mL.
Using mole = mass/molar mass to convert mass of HCl to moles
Molar mass of HCl = 1.0079 + 35.453 = 36.4609g/mol
mole = 60.4g ÷ 36.4609g/mol
mole = 1.66mol
Volume of water = 505mL = 505/1000 = 0.505L
Molarity, M = 1.66 ÷ 0.505
Molarity of HCl solution = 3.29 M
Valence electrons are important when drawing molecular structures because
a. They are closest to the nucleus of the atom and do not participate in chemical
bonding
b. They are closest to the nucleus of the atom and participate in chemical
bonding
c. They are farthest away from the nucleus of the atom and do not participate in
chemical bonding
d. They are farthest away from the nucleus of the atom and participate in
chemical bonding
Answer:
d
Explanation:
Valence electrons are in the outermost shell. They form chemical bonds with other elements, not any other electrons. Hope this helps!
Identify which statement is true about "Elements and Compounds" 1 A. Individual elements join together and constitute a compound B. Compounds have same type of atoms C. Chemical symbols represent Compounds D. Elements can be broken down into smaller substances
Answer: The Correct option is A.
Individual elements join together and constitute a compound
Explanation:
This is because Elements refer to a substance that contain a single atom.
Element is a single entity.
Compound is a substance that consist of two or more elements which are chemically join together. Elements make up a compound.
how many grams are represented by 1.45 moles of Koh? Determine your answer to the correct number of significant figures.
Answer:
[tex]\boxed {\boxed {\sf 81.4 \ g\ KOH}}[/tex]
Explanation:
We are asked to convert 1.45 moles of potassium hydroxide (KOH) to grams.
1. Molar MassThe molar mass is the mass in grams of 1 mole of a substance. The values are found on the Periodic Table. They are the same as the atomic masses but the units are grams per mole (g/mol) instead of atomic mass units (amu).
We have the compound KOH. Look up the molar masses of the individual elements.
Potassium (K): 39.098 g/mol Oxygen (O): 15.999 g/mol Hydrogen (H): 1.008 g/molThe formula for the compound has no subscripts, so there is 1 mole of each element in 1 mole of the compound. We can simply add the molar masses.
KOH: 39.098 + 15.999 + 1.008 =56.105 g/mol2. Convert Moles to GramsBased on the molar mass, there are 56.105 grams of KOH in 1 mole. Create a ratio using this information.
[tex]\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}[/tex]
We are converting 1.45 moles of KOH to grams, so we multiply by this value.
[tex]1.45 \ mol \ KOH *\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}[/tex]
The units of moles of KOH cancel.
[tex]1.45\ *\frac {56.105 \ g\ KOH}{ 1 }[/tex]
[tex]81.35225 \ g\ KOH[/tex]
3. RoundThe original measurement of moles has 3 significant figures, so our answer must have the same.
For the number we calculated, that is the tenths place. The 5 in the hundredths place (81.35225) tells us to round the 3 up to a 4.
[tex]81.4 \ g\ KOH[/tex]
Approximately 81.4 grams of potassium hydroxide are represented by 1.45 moles.
How many molecules of water vapor participate in the above reaction if 90 g of water vapor are available?
Answer:
can I see the reaction plz before I answer the question
Susan was frantic: the small diamond had disappeared from her wedding ring! It had been there this morning, before she made breakfast, so now she was ransacking the kitchen. She searched the dirty, soapy dishwater in the sink. She rummaged through the fridge, overturning a carton of milk, a bottle of sweetened orange juice, a container of potato salad and a jug of pumpkin soup. Then it was the pantry's turn. She examined the bottle of vinegar, the sugar bowl and all of the baking supplies, releasing a cloud of flour into the air. She even emptied the salt shaker onto the bench and pawed through the salt in search of the diamond. As she slumped to the concrete floor in despair, surrounded by a complete mess, she finally saw it – glittering in the dog's water bowl. Identify five mixtures mentioned in the stor
Answer:
No. 1 Susan was Frantic
No.2 panicked
No.3 determined
No.4 Despair
No.5 Releif
I really hope this helps, Good luck! :D
A gas occupies 25.3 at pressure of 790.5 mmHg. Determine the volume if the pressure is reduced to 8.04 mmHg
Answer:
2487.51.
Explanation:
As per Boyle's law temperature remaining constant the volume of an ideal gas is inversely proportional to its pressure.
pV= k
therefore, p1V1 = p2V2
here V1 = 25.3, p2 = 8.04mm Hg
pressure p1 = 790.5 mm Hg
this means that
25.3×790.5 = 8.04V2
⇒V2= 2487.51
Hence, the required volume is, 2487.51.
The pH at the equivalence point in any titration is the pH of the salt solution formed. At the equivalence point of the titration, the solution contains sodium benzoate and water. The passage states that benzoic acid is a weak acid; therefore, its conjugate base, the benzoate anion, is a stronger base than OH- and reacts with water to produce OH- and undissociated benzoic acid. The resulting solution then has a pH > 7, because of the hydroxide ions produced by this reaction. The reaction of an ion such as benzoate ion with water is called hydrolysis.
A. < 4
B. > 4 and < 7
C. = 7
D. > 7
Answer:
D. > 7
Explanation:
Benzoic acid, HX, is a weak acid that reacts with OH- as follows:
HX + OH- → X- + H2O
Where X- is produced, the conjugate base of benzoic acid.
As benzoic acid is a weak acid, benzoate ion is a strong base. A strong base has pH > 7. Right option is:
D. > 7
an archaeologist discovers an ancient wooden bowl. which isotope would most likely be used to determine its age?
a. carbon-12
b. carbon-14
c. uranium-238
d. oxygen-16
please and thank you to anyone who may know the answer.
Answer:
B
Explanation:
Question 12 of 15
Matter can undergo chemical reactions and nuclear reactions. Which
statement is true for both types of reactions?
A. The reactants are changed to form the products.
B. The reactants can be elements or compounds.
C. The products can be elements or compounds.
D. The products can be the same as the reactants.
Answer:
A. The reactants are changed to form the products.
Explanation:
Chemical reactions are reactions that involves a change in the chemical composition of substances involved while a nuclear reaction is the process of fusing together or splitting the nucleus of an atom. According to this question, matter is said to undergo both types of reaction.
However, one similarity in both chemical and nuclear reactions is that substances called REACTANTS are changed to form PRODUCTS. In nuclear reaction, the atoms joined or split are the reactants while the ones formed are the products.
Answer: A
Explanation: