Answer:
12
Explanation:
there are 12 because of the desnity
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:
6. You have a sample of H2Ois, with a mass 23.0 grams at a temperature of 46.0
temperature water would be in what state? Use reference table on page 492 for specific heat
capacity of ice). How many kilojoules of heat energy are necessary to carry out each step? Also
calculate the total amount of energy needed.
a) heat the ice to 0.0 °C?
Answer: I think it would be -23
Explanation:
1.4 Which one of the following does not fit in with the rest?
A a layer of oil on water
B cream on milk
C С water on top of the syrup in a cooldrink mixture
D a plank floating on water
Answer:
D a plank floating on water
Explanation:
Its not a mixture
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
Suppose you are titrating an acid solution with a base solution of known concentration. To calculate the concentration of the acid solution, use three steps. 1. Use the -------------- { (a) delivered volume (b) volume reading} of base --------------- { (a) after (b) to reach (c) before} the endpoint and the known concentration of the base solution to find the ------------ { (a) moles (b) mass (c) concentration} of base used. 2. Use the ------------ { (a) molar mass (b) dilution equation (c) molar ratio} to find the moles of acid from the moles of base. 3. Divide the moles of acid by the volume of -------------- { (a) base solution before (b) acid solution before (c) acid solution after} the titration to find the concentration of acid.
Answer:
1. (a) delivered volume, (b) to reach, (a) moles
2. (c) molar ratio
3. (b) acid solution before.
Explanation:
1. You must titrate the acid with a base solution of known concentration, and use the (a) delivered volume. At the endpoint, the moles of acid and base in the titration follows the chemical equation, thus, you need (b) to reach the endpoint. With volume and concentration of the base we can find its (a) moles
2. With the (c) molar ratio, we can relate the moles of base with the moles of acid
3. When we have the moles of acid, we just need the volume of (b) acid solution before the titration to find molarity of the acid.
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:
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
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
Determine the kinetic energy of a 600-kg roller coaster car that is moving at a speed of 18 m/s.
Answer:
97200 J
Explanation:
Applying,
K.E = mv²/2.................. Equation 1
Where K.E = Kinetic Energy, m = mass of the roller coaster car, v = velociety of the roller coaster car.
From the question,
Given: m = 600 kg, v = 18 m/s
Substitute these values into equation 1
K.E = (600×18²)/2
K.E = 97200 J.
Hence the kinetic energy of the car is 97200 J
In explosive combustion the rapid expansion of --------------- causes explosion and the production of ------------------
Answer:
Volume; high temperature and pressure
Explanation:
In an explosive combustion the rapid expansion of the volume causes explosion and the production of high temperature and pressure.
The substance is usually in a confined place and the expansion usually reaches a breaking point in which it is expelled from the space usually accompanied with a loud noise and high amount of temperature and pressure change thereby releasing its gas constituents.
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.
Considering the temperature vs. time graph below, how does the temperature at the beginning of a change of state
compare with the temperature at the end of the change?
Answer:
The temperature on the graph is higher at point 5 than at point 1. The correct answer is the last answer choice that you showed.
Explanation:
The temperature at point 1 is -10 degrees Celsius, while the temperature at point 5 is 120 degrees Celsius. This is a 1300% increase.
See the calculation here: https://www.calculatorsoup.com/calculators/algebra/percent-change-calculator.php?v_1=-10&v_2=120&action=solve
I hope this helps.
Which functional group defines an alcohol?
0 – PO4
O =
= 0
o
– Na
o
- ОН
If a sample of air initially occupies 240L at 2 atm how much pressure is required to compress it to 20L at constant temperature
Answer:
24 atm.
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 240 L
Initial pressure (P₁) = 2 atm
Final volume (V₂) = 20 L
Temperature = constant
Final pressure (P₂) =?
The final pressure required, can be obtained by using the Boyle's law equation as shown below:
P₁V₁ = P₂V₂
2 × 240 = P₂ × 20
480 = P₂ × 20
Divide both side by 20
P₂ = 480 / 20
P₂ = 24 atm
Thus, the final pressure required is 24 atm.
Help!! Please explain how you get the answer
Answer:
5 moles
Explanation:
First, write out the balanced equation:
2Al + Fe₂O₃ → Al₂O₃ + 2Fe
Reaction ratio of Al to Fe₂O₃ is:
2 : 1
This means 2 moles of Al will react with 1 mole of Fe₂O₃
Al: 5 mol
Fe₂O₃: 3 mol
Multiply the reaction to get moles of both reactants you have:
2 : 1 (×⁵/₂) = 5 : ⁵/₂
2 : 1 (×3) = 6 : 3
In other words, 5 moles of Al will react with ⁵/₂ moles of Fe₂O₃;
And 3 moles of Fe₂O₃ will react with 6 moles of Al;
But, we do not have 6 moles of Al, therefore only the 5 moles of Al available will react;
5 moles of Al reacts with ⁵/₂ moles of Fe₂O₃, as we can see from the ratios we calculated above, the remaining ¹/₂ mole of Fe₂O₃ will not react;
We say that Al is the limiting reactant because all the Al will react but all the Fe₂O₃ does not (i.e. it is in excess);
Next and last, the reaction ratio of Al to Fe is:
2 : 2 or, more simply 1 : 1
This means the moles of Al that reacts is the equal to the moles of Fe produced from the reaction;
We've established that 5 moles of Al will react with ⁵/₂ moles of Fe₂O₃, so 5 moles of Fe will also be produced (since the ratio is 1 : 1);
You could also work this out using the moles of Fe₂O₃ that react;
The reaction ratio of Fe₂O₃ to Fe:
1 : 2
So the moles of Fe produced is 2× the moles of Fe₂O₃;
If ⁵/₂ moles of Fe₂O₃ reacts, then simply multiply this by 2 which is 5 moles
Will give brainliest
process name of liquid bromine to bromine vapor
Answer:
evaporation, vaporisation, boiling if change occurs at boiling point
Explanation:
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!
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
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.
What type of experiment did the student in the passage perform?
Answer:
Passage?
Explanation:
How many moles are in 2.11 x 1014 molecules of LiBr?
Answer: There are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.
Hence, moles in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr are calculated as follows.
[tex]Moles = \frac{2.11 \times 10^{14}}{6.022 \times 10^{23}}\\= 12.71 \times 10^{-9}[/tex]
Thus, we can conclude that there are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Explain why rubbing an alkali like bicarbonate of soda onto an acidic bee sting can ease the pain ?
What is the mass of 0.251 moles of water? Using dimensional analysis show work
[tex]1 \text{ mol of H}_2 \text{O} \equiv 18 \text{ g} \implies 0.251 \text{ moles of H}_2 \text{O} \equiv 4.518 \text{ g}[/tex]
If the pressure of a 2.00 L sample of gas is 50.0 kPa, what pressure does the gas exert if its volume is decreased to 20.0 mL?
Which equation should you use?
__________________________________________________________
Which equation should you use?
B. P₁V₁=P₂V₂
What is the new pressure?
✔ 5000 kPa
__________________________________________________________
Explanation:The problem gives initial volume (2.00 L), final volume (20.0 mL), and initial pressure (50.0 kPa). Then it asks to find the final pressure. Answer B has all these variables, with P₁=initial pressure, P₂=final pressure, V₁=initial volume, and V₂=final volume. Plug the given values into the equation and then solve for the unknown value, which is P₂, final pressure.
When plugging in the values, use consistent units. 2L=2000 mL, I chose to make the consistent unit in mL. You'll get the same answer if you choose to use L as the consistent unit.
[tex]2000*50=20*P2[/tex]
[tex]100000=20*P2[/tex]
Divide both sides by 20
[tex]100000/20=(20*P2)/20[/tex]
[tex]5000=P2[/tex]
Here's a photo of Edge just incase.
The molar mass of copper(II) chloride (CuCl2) is 134.45 g/mol. How many formula units of CuCl2 are present in 17.6 g of CuCl2?
Answer:
7
Explanation:
took test
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.
Which force pulls earth and the sun toward each other?
Answer:
the correct answer is gravity
Answer:
the gravitational pull so gravity (b)
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.
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
Will give Brainliest and 20 points
Answer:
k = 1.26 x 10^-12
Its extremely small.
It follows that when k is small... The equilibrium concentration of Reactant is large and More than Product.
Option C should be your answer