Please help
What is the formula for pentaboron nonahydride?

Answers

Answer 1
From what I remember it is B5H9

Related Questions


How many grams of H2 are needed to react with 2.85 g of N2?

Answers

Hey
The answer is 0.616 grams

What is the energy change when a 777.1 g sample of water has
an initial temperature of 57.3 °C and a final temperature of
42.6 °C

Answers

Answer:

 -47749.69 joule energy release.

Explanation:

Given data:

Mass of water = 777.1 g

Initial temperature = 57.3°C

Final temperature = 42.6 °C

Energy change = ?

Solution:

Specific heat capacity of water is 4.18 J/g.°C

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 42.6 °C - 57.3°C

ΔT = -14.7°C

Q = 777.1 g × 4.18J/g.°C ×  -14.7°C

Q =  -47749.69 J

 -47749.69 joule energy release.

are all elements created equal? Provide evidence for why or why not.​

Answers

yes. even though they have different characteristics, they are all made out of atoms; electrons, neutrons, and protons along with a neutral charged nucleus

Which best describes the changes occurring to the earth's surface over time?

1.) Mountains are gradually being worn down, but no new ones are formed

2.) New mountains are being formed as old mountains are gradually worn down

3.) More mountains are gradually formed as the oceans recede.

4.) New mountains are only formed under the oceans.

Answers

Answer:

I would say the answer is 2

The formation of new mountains due to tectonic movements is reporting now whereas, some of  the olden mountains are worn down. Thus option 2 is correct.

What is tectonic movement?

Earth crests is made of tectonic plates of different sizes and shapes. These plates were not apart and was one in the earlier times of earth and no separate continents were there. When heat in the atmosphere made the magma hot and the hot fluid flow makes the plate moving.

The tectonic plate movement is different in different regions and its results be different. Some movements results in the formation of mountains mostly when the plates are moving each other and one plate rise the edge of others.

Some movement results in islands, folded mountains, volcanic mountains etc. These mountains may worn down over time and there is a possibility of formation of new mountains in regions where significant plate movement occurs.

To find more about  plate movement, refer the link bellow:

https://brainly.com/question/3970445

#SPJ2

2210.20 J of energy is equal to how many calories?​

Answers

Answer:

528.25 Calories

Explanation:

From the question given above, the following data were obtained:

Energy in Joules = 2210.20 J

Energy in calories =?

We can convert 2210.20 J to calories by doing the following:

4.184 J = 1 cal

Therefore,

2210.20 J = 2210.20 J × 1 cal / 4.184 J

2210.20 J = 528.25 Calories

Thus, 2210.20 J is equivalent to 528.25 Calories.

The unit of electrical resistance is the: ohm-cm ohm volt ampere

Answers

Answer:

Ohm/ Current = Resistance

Explanation:

Answer:

Ohm

Explanation:

2. How many Cu atoms have a mass of 4.500x10^5 amu? ​

Answers

Answer:

63.55

Explanation:

4.500 x 10^5 amu x 1 Cu atom / 63.55 amu = 7081 Cu Atom

Cu 1 x 63.55 = 63.55

What is the density if the mass is 120g and the volume of the object is 96mL?

Answers

Answer:

1.25 g/cm^3

Explanation:

D = M/V

Mass is 120g

Volume is 96 ml

So you do 120/96 and you get your final answer as 1.25

Hope it helped!

A blueberry bush uses energy from the sun to make sugars. which set of enerdy transformations BEST describe this process?

Answers

Reword it I’m confused

A compound is found to contain 25.24 % sulfur and 74.76 % fluorine by weight. The molecular weight for this compound is 254.14 g/mol. What is the molecular formula for this compound

Answers

Answer:

[tex]S_2F_{10}[/tex]

Explanation:

Hello!

In this case, since the empirical formula of a chemical compound is determined by assuming the by-mass percentages are masses, we can firstly compute the moles of sulfur and fluorine based on their atomic masses:

[tex]n_S=25.24gS*\frac{1molS}{32.01gS}=0.789molS\\\\n_F=74.76gF*\frac{1molF}{19.00gF}=3.93molF[/tex]

Next, we compute the subscript of each element in the formula by dividing each moles by the fewest moles:

[tex]S=\frac{0.789}{0.789}=1\\\\F=\frac{3.93}{0.789} =5[/tex]

Whose molar mass is 127.01 g/mol. Now, we can compute the ratio between the molecular and empirical formulas as follows:

[tex]ratio=\frac{254.14}{127.01} =2[/tex]

Thus, the molecular formula is:

[tex]S_2F_{10}[/tex]

Regards!

Is the cell membrane a factory part or worker? Please explain what it does as a factory part or worker

Answers

It is probably a worker bc it lets things in and out of the cell and stops harmful things from entering the cell

Answer:

hey i saw you asked about the kinetic energy lab report on edg and i was wondering if you ever finished it and could send it me plzzzzzzzz

Explanation:

R equals The formula for Ohm's law can be written: R equals _____. I / V V / I I x V

Answers

Answer:

R = V / I

Explanation:

Ohm's Law:

V = I * R , V = voltage , I = current , R = resistance

rearranging to solve R,

R = V / I

Answer:

R = V / I

Explanation:

HELP PLEASE! Which of these is an example of the climate of a region?
Continental
Foggy
Overcast
Sunny

Answers

Continental !!!!!!!!!!!!!

Answer:

Continential

Explanation:

foggy, overcast, and sunny are all examples of weather

If 2.35 L hydrogen gas react with nitrogen gas to form nitrogen trihydride, how many grams of nitrogen will be needed for the reaction to be completed?



0.98 g


0.49 g


21.93 g


1.47 g

Answers

Answer:

1.47 g

Explanation:

Which type of change, chemical or physical, is a change on the atomic level?

Answers

Explanation:

Examples of chemical changes include, rusting, fire, and overcooking. Nuclear changes occur when the nuclei of atoms are rearranged to form new atoms. Examples of nuclear changes include atomic fission, nuclear fusion, and the energy of sun and stars.

When atoms and molecules speed up or slow down, that is a physical change. When they change state from liquid to solid or from gas to liquid, that is a physical change. When a substance is dissolved by water or some other solvent, a new substance has not really been formed.

ltennelmessifcb avatar
ltennelmessifcb
45 minutes ago
Chemistry
Senior High School
You are given 600 grams of sodium chloride (NaCl), but you are planning to purify the substance and extract just the sodium. How many moles of Na can you theoretically extract from 600 grams of NaCl? Explain your reasoning.

Answers

Moles of Na theoretically extract : 10.256

Further explanation

Given

600 g of NaCl

Required

moles of Na

Solution

Na can be electrolyzed from NaCl(molten)

Na⁺ + e⁻⇒ Na

Cl⁻⇒1/2 Cl₂ + e⁻

Overall reaction :

NaCl⇒Na + 1/2 Cl₂ x2

2NaCl⇒2Na + Cl₂

mol of NaCl(MW=58.5 g/mol) :

= 600 g : 58.5 g/mol

= 10.256

From the equation, mol ratio of NaCl : Na = 2 : 1, so :

mol Na = mol NaCl = 10.256

Why are salt solutions not used to treat the roads during snow events when the temperature is below -15 degrees Celsius? *

A. Salts are nonelectrolytes and do not demonstrate the Van't Hoff Factor.
Therefore the freezing point cannot be depressed lower than -15 C.

B.The solubility of a salt will decrease with decreasing temperature making it even more difficult to concentrate a solution. The maximum quantity that can saturate a solution and attain the maximum molality that aligns with solubility values at that low of a temperature cannot provide the multiplier high enough to depress the freezing point to temperatures below -15 C.

C.Salt has a maximum molality of 0.6m.

D.Salts can melt ice but cannot prevent freezing.

Answers

Answer:

i think thats c

Explanation:

HELP ASAP! I will give brainiest if you answer all questions correctly.

28) Choose the best answer.

Calculate the amount of heat required or released. You will need to use your Periodic Table, Table B-3 and Table B-4, in your Chemistry Reference Guide.

How much heat is required to raise the temperature of 155 g of liquid ammonia (NH3) at 200 K to ammonia gas at 300 K? Ammonia boils at 240 K.

261 kJ
-204kJ
209kJ
-88kJ
300 kJ



29) Choose the best answer.

Calculate the amount of heat required or released. You will need to use your Periodic Table, Table B-3 and Table B-4, in your Chemistry Reference Guide.

How much heat would be needed to raise the temperature of 255 grams of ice at 253 K to steam at 393 K?

-204kJ
300 kJ
209kJ
-88kJ
788 kJ



30) Choose the best answer.

Calculate the amount of heat required or released. You will need to use your Periodic Table, Table B-3, Table B-4, and Table B-5 in your Chemistry Reference Guide.

How much heat is lost when 2012 g of H2O at 400 K is changed into ice at 263 K?

300 kJ
-880 kJ
299 kJ
-204 kJ
-6201 kJ

Answers

Answer:

28). 261

29). 788

30).-6201

Explanation:

I just took lesson and it said those were correct, I added screenshots of the lesson if you need it :)

66.41 g of Copper [Cu] are combusted with 8.56g of Oxygen [O] to produce a
compound. What is the empirical formula of the compound?

Answers

The empirical formula of the compound : Cu₂O

Further explanation

Given

66.41 g Cu

8.56 g O

Required

The empirical formula

Solution

1. Find mol

Cu(Ar 63.5 g/mol)

mol = mass : Ar

mol = 66.41 : 63.5

mol = 1.046

O(Ar=16 g/mol)

mol = 8.56 : 16

mol = 0.535

2. mol ratio

Cu : O (divide by smallest mol⇒0.535) :

[tex]\tt \dfrac{1.046}{0.535}\div \dfrac{0.535}{0.535}=2\div 1[/tex]

How many moles of Ca are in 1.25x1023 atoms?

We used two conversion factors in this unit, they are provided below. It is your responsibility to know which conversion factor to use!

Avogadro’s number: 6.02x1023 atoms = 1 mole

Molar mass of calcium: 40.078 g Ca = 1 mol Ca


A. 3.12x10^21 mol


B. 0.21 mol


C. 3.12 mol


D. 0.21x10^21 mol

Answers

Answer:

B. 0.21 mol

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Atomic Structure

Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:

Step 1: Define

1.25 × 10²³ atoms Ca

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Set up:                              [tex]\displaystyle 1.25 \cdot 10^{23} \ atoms \ Ca(\frac{1 \ mol \ Ca}{6.022 \cdot 10^{23} \ atoms \ Ca})[/tex]Multiply:                            [tex]\displaystyle 0.207572 \ mol \ Ca[/tex]

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

0.207572 mol Ca ≈ 0.208 mol Ca

snow and ice absorbs much of the Sun's radiant energy

True or False?

Answer with "True" Or "False" please, thank you.

Answers

Answer: True

Explanation: I have done this before but I hope this helps.

A neutral atom has the following electronic configuration: 1s2 2s2 2p6 3s2 3p5
How many protons are in the atomic nucleus and to which group of the periodic table does this element belong?

Answers

Answer:

Number of protons=17

Halogen

Explanation:

Given,

The electronic configuration:[tex]1s^2, 2s^2, 2p^6, 3 s^2, 3 p^5[/tex]

Atomic number= 2+2+6+2+5 = 17

Chlorine has the atomic number 17.

Symbol of chlorine= Cl

We know that,

The number of protons is equal to the atomic number.

Number of protons=17

And Chlorine belongs to the halogen group of the periodic table.

(3)
Calculate the entropy change when a sample of argon at 25 °C and 1.00 atm in a container
of volume 500 cm3 is compressed to 50 cm3 and cooled to -25 °C.
For argon, Cpm = 20.786) K-Imol-1. Assume that argon behaves perfectly.

Answers

Answer:

[tex]\Delta s=-23.0\frac{J}{mol*K}[/tex]

Explanation:

Hello!

In this case, since the entropy change when an ideal gas undergo both a volume and temperature change is computed by:

[tex]\Delta s =Cp*ln(\frac{T_2}{T_1} )-R*ln(\frac{P_2}{P_1} )[/tex]

Whereas the molar Cp is 20.786 J/(mol*K) and the final pressure is computed via the Boyle's law:

[tex]P_2=\frac{1.00atm*500cm^3}{50cm^3}=10 atm[/tex]

Thus, we plug in the data (temperatures in Kelvin) to obtain:

[tex]\Delta s =20.786\frac{J}{mol*K} *ln[\frac{(-25+273)K}{(25+273)K} ]-8.3145\frac{J}{mol*K}*ln(\frac{10atm}{1atm} )\\\\\Delta s=-23.0\frac{J}{mol*K}[/tex]

Best regards!

in an electron dot diagram of fluorine , how many dots should be drawn around the elements symbol

Answers

Answer:

7 dots

Explanation:

Calculate the density (in grams per milliliter) of the following gas at 97 °C and 755 mm Hg Sulfur dioxide (SO2)

Answers

Answer:

Density = 2.09×10⁻³ g/mL

Explanation:

We solve this problem from the Ideal Gases Law.

P . V = n . R . T

We know that in STP conditions 1 mol of any gas occupies 22.4 L. So we can compare both situations.

22.4 L = 22400 mL

(P₁ . V₁) / T₁ = (P₂ . V₂) / T₂

We make some conversions:

97°C + 273 = 370 K

755 mmHg . 1 atm / 760mmHg = 0.993 atm

We replace data: (1 atm . 22400 mL) / 273 K = (0.993 atm . V₂) / 370 K

((1 atm . 22400 mL) / 273 K) . 370K = 0.993 atm . V₂

V₂ = 30359 atm . mL / 0.993 atm → 30573 mL

Under those conditions (97 °C and 755 mm Hg) 1 mol of gas is contained in 30573 mL.

We determine the amount of gas: 1 mol of SO₂ weighs 64.06g

Density = m/V → 64.06 g / 30573 mL = 2.09×10⁻³ g/mL

Question (2) If your car
gets 27.8 miles to the gallon, how many liters of gasoline are necessary to travel 112 km?
This problem can be solved in short steps or in one longer step. In either case, please show your work.
Use the following conversion factors:
1 mi = 1.609 km
1 gal = 3.785 L

Answers

Answer:

9.48 L.

Explanation:

Hello!

In this case, as the problem mentions a long way to solve it, we are going to apply it because it can provide the answer more rapidly; thus, considering that 112 km are required, 1 mile equals 1.609 km and 1 gallon equals 3.785 liters, we can set up the proportional factor as shown below:

[tex]112km*\frac{1mi}{1.609 km}*\frac{1gal}{27.8mi}*\frac{3.785L}{1gal}[/tex]

Whereas km, mi and gal are cancelled out as it turns out in L; therefore the required liters are:

[tex]9.48L[/tex]

Best regards!

PLEASEEEE PLEASE HELP MEEEE... i begg you

Answers

Answer:

the answer to the first one is B and the second one is that the volume is a control, the heart rates are dependent, the how music played is controlled, how the heart rates are measured is controlled, the music played is independent

A compound consists of atoms of two or more elements combined in a _______.

Answers

Answer: small, whole-number ratio

Explanation: 1) A compound consists of atoms of two or more elements combined in a small, whole-number ratio. In a given compound, the numbers of atoms of each of its elements are always present in the same ratio

Answer:

fixed proportion

Explanation:

Write the following elements in increasing order of atomic radius.
Ca, Mg, Be, Sr

Answers

Answer:

In increasing order:

Sr, Ca, Mg, Br

How many grams are in 0.75 moles of zinc?

Answers

Answer:

There are 65.38 grams are in 0.75 moles of zinc?

explain :

We assume you are converting between moles Zinc and gram. You can view more details on each measurement unit: molecular weight of Zinc or grams The molecular formula for Zinc is Zn. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Zinc, or 65.38 grams.

I hope it will be helpful for you
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