I will go to the app and give you brainly Est if u answer correctly ASAPPPPP

Answer:

62.9%

Explanation:

Step 1: Given data

Step 2: Calculate the mass lost of water

We will use the following expression.

mH₂O = mNa₂CO₃.xH₂O - mNa₂CO₃

mH₂O = 71.5 g - 26.5 g = 45.0 g

Step 3: Calculate the percent of water in the hydrate sodium carbonate

We will use the following expression.

%H₂O = mH₂O / mNa₂CO₃.xH₂O × 100%

%H₂O = 45.0 g / 71.5 g × 100%

%H₂O = 62.9%

The initial temperature of water in the beaker is 20⁰C .

Answer:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds :)

Answer:

CH4 + 4Cl2 ===> CCl4 + 4HCl

Explanation:

I am pretty sure atleast?

Answer: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

Explanation: definition

Answer:

0.174kg of Ore are required

Explanation:

The ore of 37.3% in nickel by mass means that in 100g of ore there are 37.3g of nickel. As we need to obtain 65g of nickel we can convert this mass to mass of ore using the conversion factor (100g Ore / 37.3g Nickel) as follows:

65g of nickel * (100g Ore / 37.3g Nickel) = 174g of Ore are needed to have 65.0g of nickel. In kilograms:

174g Ore * (1kg / 1000g) =

Answer:

b. a type of gas is evolved ( hydrogen gas )

2.04 mol CBr₄

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Organic

Atomic Structure

Step 1: Define

675 g CBr₄

Step 2: Identify Conversions

Molar Mass of C - 12.01 g/mol

Molar Mass of Br - 79.90 g/mol

Molar Mass of CBr₄ - 12.01 + 4(79.90) = 331.61 g/mol

Step 3: Convert

[tex]\displaystyle 675 \ g \ CBr_4(\frac{1 \ mol \ CBr_4}{331.61 \ g \ CBr_4}) = 2.03552 \ mol \ CBr_4[/tex]

Step 4: Check

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

2.03552 mol CBr₄ ≈ 2.04 mol CBr₄

Answer:

[tex]\boxed {\boxed {\sf About \ 2.04 \ moles \ of \ CBr_4}}[/tex]

Explanation:

1. Define Formula

The compound is carbon tetrabromide. The tetra indicates 4 atoms of bromine.

2. Find Molar Mass

There are 2 elements in this compound: carbon and bromine. Use the Periodic Table to find the molar masses of these elements.

The molar mass is based on the number of atoms in the compound. The compound has 1 atom of carbon and 4 atoms of bromine.

CBr₄= 1(12.011 g/mol) + 4(79.90 g/mol)

= 12.011 g/mol+319.60 g/mol = 331.611 g/mol

3. Convert Grams to Moles

We want to convert 675 grams to moles. We should use the molar mass as a fraction.

[tex]\frac{331.611 \ g \ CBr_4}{1 \ mol \ CBr_4 }[/tex]

Multiply by the given number of grams.

[tex]675 \ g \ CBr_4 *\frac{331.611 \ g \ CBr_4}{1 \ mol \ CBr_4 }[/tex]

Flip the fraction so the grams of CBr₄ will cancel.

[tex]675 \ g \ CBr_4 *\frac{1 \ mol \ CBr_4 }{331.611 \ g \ CBr_4}[/tex]= [tex]675 \ *\frac{1 \ mol \ CBr_4 }{331.611 \ }[/tex]

[tex]\frac{675 \ mol \ CBr_4 }{331.611 \ }[/tex] = [tex]2.03551752 \ mol \ CBr_4[/tex]

4.Round

The original measurement, 675 grams has 3 significant figures (6,7 and 5), so our answer must have the same.

For the answer we found, 3 sig figs is the hundredth place.

[tex]2.03551752 \ mol \ CBr_4[/tex]

The 5 in the thousandth place tells us to round the 3 to a 4.

[tex]\approx 2.04 \ mol \ CBr_4[/tex]

There are about 2.04 moles of carbon tetrabromide in 675 grams.

Answer:  The mass of 405 mL of ethylene glycol is 444.3 g.

Explanation:

Density is defined as the mass contained per unit volume.

[tex]Density=\frac{mass}{Volume}[/tex]

Given :

Density of the ethylene glycol= [tex]1097g/L[/tex]

Volume of the ethylene glycol= [tex]405ml[/tex]  = 0.405 L   (1L=1000ml)

Mass of  the ethylene glycol = ?

Putting in the values we get:

[tex]1097g/L=\frac{x}{0.405L}[/tex]

[tex]x=444.3g[/tex]

Thus the mass of 405 mL of ethylene glycol is 444.3 g

Answer: Alloy

Explanation: gold is an alloy, or mixture of metals

Answer:

it causes the cells to become flaccid and the stomata openings to close

Explanation:

the stomata closes to reduce water loss

When a plant is losing water at a greater rate than it can be replaced by its roots, then in such a case, the stomata will get close to reduce the loss of water.  

• Generally, the opening of stomata takes place in the day and gets close at night. To prevent the loss of water stomata get close during the night.  

• However, in certain cases, even during the day, when the plant experiences loss of water due to conditions like drought then stomata remain close during the day also.  

• This opening and closing of stomata take place as a response to the signals from the external environment.

Therefore, when more amount of water is loosing from the plant than getting absorbed by the roots, the stomata gets the signal to remain close to prevent water loss and death of the plant.

To know more about stomata and water loss:

https://brainly.com/question/2611673

Answer:

0.0659M

Explanation:

...5,15g  of Fe(NO₃)₃ is dissolved...

Molar concentration is the amount of moles presents in 1L of solution. To solve this question we need to find the moles of iron nitrate, Fe(NO₃)₃ present in the 323mL of solution:

Moles Fe(NO₃)₃ -Molar mass 241.86g/mol-:

5.15g Fe(NO₃)₃ * (1mol / 241.86g) = 0.0213moles Fe(NO₃)₃

And molarity is:

0.0213moles Fe(NO₃)₃ / 0.323L = 0.0659M

Answer:

Alkali metals are among the most reactive metals. This is due in part to their larger atomic radii and low ionization energies. They tend to donate their electrons in reactions and have an oxidation state of +1. ... All these characteristics can be attributed to these elements' large atomic radii and weak metallic bonding.

Explanation:Because they have just one valence electron, group 1 elements are very reactive. As a result, they are found in nature only in combination with other elements. Alkali metals are all solids at room temperature. ... From the top to the bottom of group 1, the elements have heavier, more reactive atoms.

hope it helped :)

Answer:

Mass Pressure and density.

Explanation:

Answer:

N2H4 + 3O2 → 2NO2 + 2H2O

Explanation:

Answer: The mole fraction of chloroform in this solution is 0.41

Explanation:

To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]

a) moles of [tex]CHCl_3[/tex]

[tex]\text{Number of moles}=\frac{49g}{119g/mol}=0.41moles[/tex]

b) moles of [tex]CH_3COBr[/tex]

[tex]\text{Number of moles}=\frac{73g}{123g/mol}=0.59moles[/tex]

To calculate the mole fraction, we use the formula:

[tex]\text{Mole fraction of a component}=\frac{\text{Moles of the component}}{\text{total moles}}[/tex]

[tex]\text{Mole fraction of chloroform}=\frac{\text{Moles of chloroform}}{\text{total moles}}=\frac{0.41}{0.41+0.59}=0.41[/tex]

The mole fraction of chloroform in this solution is 0.41

Answer:

Meiosis

Explanation:

They just split in four.

Answer:

Hydrogen chloride (HCl) and Calcium hydroxide (CaOH). (see balanced equation below)

Explanation:

In a neutralization reaction as is the case of the question (see attachment), an acid would be neutralized by a base to form salt and water.

The most plausible reactants for the reaction given the number of moles of the product, is therefore Hydrogen chloride (HCl) and Calcium hydroxide (Ca(OH)2).

[tex]HCl _{(aq)} + Ca(OH)_{2} _{(aq)}[/tex] →[tex]CaCl_{2}_{(s)} + H_{2} O_{(l)}[/tex]

Let me know if this was helpful.

Answer:

6. false.  

chemical energy to heat and mechanical. Mechanical that runs the factory in the photo, and Heat energy that rises up in the atmosphere to join the other carbon

molecules in the air. 7. True. The arrow letter A is the transfer of solar power

from the sun, to a chemical reaction to produce food for the plant, which is

called photosynthesis. The leaves in the plant has chlorophyll that absorbs light

energy and transforms it to food.8. The answer would be letter C and F. C because It is

during the burning of the fossil fuels that the carbon dioxide is release into

the atmosphere. When burning the fossil fuels the carbon that was inside the

fossils is released. This also happens with diesel and other forms of natural

gas. While, F is because plant

respiration releases some of the carbon remains of the photosynthesis. While

plants do absorb carbon dioxide, part of their end product also includes reformed

carbon dioxide. Most of the other processes in the phot uses carbon or absorbs

carbon dioxide to aid their sustenance.9. A carbon cycle for living things would be A or B to F

wherein the plants absorb carbon dioxide to aid their production of food, and

then releasing carbon dioxide again as a by product of their food production.

This also happen to aquatic plants.An example of a non-living carbon cycle would be, D or E to

C. This would be the absorption of the carbon on our sea waters or to our soil,

this then gets trapped in there until it is release like through the forms of

fossil fuel burning.10. The law of conservation of mass and energy states that

matter can neither be created nor destroyed, this is very much evident in the

carbon cycle. Because the carbon from the light energy from the sun, or in our

atmosphere, ends up back to our atmosphere just to continue its cycle. The fact

that the carbon cycle is a cycle not just a linear equation proves that energy

can neither be created nor destroyed.

Explanation:

Answer: A chemical symbol is a one- or two-letter designation of an element. Compounds are combinations of two or more elements. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.

Answer:

the effects that the scientists are causing by manipulating varuables

The complete question is shown in the image attached

Answer:

See explanation

Explanation:

In a molecule, the direction of the dipole moment also shows the direction of the shift in electron density. Let me give you an instance. In HCl, the dipole points towards the chlorine atom. This implies that the bond is polar and the chlorine atom accommodates the greater share of the electron density of the H-Cl bond. The negative partial charge rests on the more electronegative atom (chlorine in this case) while the partial positive charge rests on the more electropositive atom(hydrogen in this case). Recall that the difference in electron density between the two atoms creates this polarity.

Having said that much, let me come to the issue of electronegativity and bond polarity. The polarity of bonds depends on the electronegativity difference between atoms. I have just established that the H-Cl bond is polar owing to the difference in electronegativity between hydrogen and chlorine. If I replace the chlorine atom in the molecule with another hydrogen atom, the molecule is no longer polar because the difference in electronegativity of a H-H bond is zero.

Lastly, let me talk about electronegativity difference and bond character. The magnitude of electronegativity difference between atoms determines the bond character. If the electronegativity difference between bonding atoms is;

less than 0.4, the bond is a pure covalent bond

between 0.4 - 1.8, the bond is a polar covalent bond

greater than 1.8, the bond is a pure ionic bond  

Answer:

0.404M

Explanation:

...To make exactly 100.0mL of solution...

Molar concentration is defined as the amount of moles of a solute (In this case, nitrate ion, NO₃⁻) in 1 L of solution.

To solve this question we need to convert the mass of Fe(NO₃)₃ to moles. As 1 mole of Fe(NO₃)₃ contains 3 moles of nitrate ion we can find moles of nitrate ion in 100.0mL of solution, and we can solve the amount of moles per liter:

Moles Fe(NO₃)₃ -Molar mass: 241.86g/mol-:

3.26g * (1mol / 241.86g) =

0.01348 moles Fe(NO₃)₃ * (3 moles of NO₃⁻ / 1mole Fe(NO₃)₃) =

0.0404 moles of NO₃⁻

In 100mL = 0.1L, the molar concentration is:

0.0404 moles of NO₃⁻ / 0.100L =

Answer:

hope this help

Explanation:

change: volume of solid , volume of liquid , the volume of gases

not change: the shape of solid , the shape of liquid , the shape of gases

Answer:

Name

Sulfur

Atomic Mass

32.066 atomic mass units

Number of Protons

16

Number of Neutrons

16

Number of Electrons

16

Explanation:

Answer:

Explanation:

16 protons

16 electrons

16 neutrons

Explanation:

By Factor Theorem,

(2)^m - 3(2)^(m-1) + 4(2) - 4 = 0.

=> 2^m - 1.5 * 2^m + 4 = 0

=> 4 - 0.5 * 2^m = 0

=> 0.5 * 2^m = 4

=> 2^m = 8

=> m = 3.

Hence the value of m is 3.

Answer: The salinity of ocean water is 34 ppt.

Explanation:

Salinity is defined as the number of grams of salts present per kilogram of seawater. It is expressed in parts per thousand.

The formula used to calculate the salinity of ocean water or sea water is:

[tex]\text{ Parts per thousand}=\frac{\text{Mass of salts}}{\text{Mass of sea water}}\times 1000[/tex]

We are given:

Mass of salts = 17 g

Mass of sea water = 500 g

Putting values in above equation, we get:

[tex]\text{ Parts per thousand}=\frac{17g}{500g}\times 1000\\\\\text{ Parts per thousand}=34[/tex]

Hence, the salinity of ocean water is 34 ppt.

The heat produced from 48 g Aluminium = -578

Given

Reaction

2 Al + 3 CuSO4 → 3 Cu + Al2(SO4)3 ∆H = -680 kJ

48 g of Aluminum

Required

Heat released

Solution

mol of Aluminium = mass : Ar Al

mol = 48 g : 27 g/mol

mol = 1.78

From the reaction, heat released for 2 moles Al, so for 1.78 Al, the heat released :

[tex]\tt \dfrac{1.7}{2}\times -680~kJ=-578~kJ[/tex]