WILL MARK BRAINLIEST please

Answer:

1.59g/mL

Explanation:

(777.7572 – 45.8772)g / (20.0) ml = (31.8800 g) / (20.0 ml) = 1.59 g/ml

Answer:

alkali metals

Explanation:

alkali metals only have one valence electron, meaning they are extremely reactive. they are considered the most reactive on the periodic table.

Answer:

C. equals the mass of 1 mL of water at 4°C

Explanation:

Answer:

An unknown being weighed is hygroscopic. - operative error

One component of a mixture being analyzed quantitatively by gas chromatography reacts with the column packing. - methodic error

The tip of the pipet used in the analysis is broken. - instrumental error

In measuring the same peak heights of a chromatogram, two technicians each report different heights - operative error

Explanation:

In chemical analysis, operative errors are that largely introduced into the measurement because of variation of personal judgements of analysts. It is also a personal error that emanates solely due to the analyst.

A methodic error arises as a result of adopting defective experimental methods. For example, a column packing that reacts with a component of the mixture is used in the gas chromatography.

Instrument error refers to the error of a measuring instrument, for instance, the use of a pipette with a broken tip.

Answer:

The metal is Copper

Explanation:

Matter is composed of atoms, which is the smallest indivisible particle of an element. The atom of an element consists of three subatomic particles namely: proton, electron and neutron etc.

The proton, which is the positively charged particle, is equal to the electron, which is the negatively charged particle. The proton number of the atom is the ATOMIC NUMBER of an element.

In the periodic table, the element with atomic number 29, which also means proton number 29 is Copper (Cu).

Answer:

m = 455,6 g

Explanation:

The mass can be determined by calculating the amount of substance times the molar mass:

m = n * M

To do this, you first have to calculate the molar mass of sodium oxalate. It is made up of the molar masses of the individual atoms. The molecular formula of sodium oxalate is:

[tex]Na_{2}C_{2}O_{4}[/tex]

M(Na) = 23 g/mol; M(C) = 12 g/mol; M(O) = 16 g/mol

M(Na2C2O4) = 2 * M(Na) + 2 * M(C) + 4 * M(O)

M(Na2C2O4) = 2 * 23 g/mol + 2 * 12 g/mol + 4 * 16 g/mol

M(Na2C2O4) = 134 g/mol

m = n * M

m = 3,4 mol * 134 g/mol

m = 455,6 g

Answer:

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

[tex]a = \frac{f}{m} \\ [/tex]

where

a is the acceleration

f is the force

m is the mass

From the question

f = 20 N

m = 5 kg

We have

[tex]a = \frac{20}{5} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

Ans : 22.86 gm of Aluminium

Solution,

                        3FeO + 2Al ---> 3 Fe + [tex]Al_{2}O_{3}[/tex]

Given                   3          2                    

Find                    1.27       x

By the given gms of FeO find its mole and put the moles in the find,

                                       [tex]n = \frac{given mass}{molecular mass}[/tex]

                  Given mass of FeO is 91.8

                   Molecular mass of FeO is 71.8

                                         n = [tex]\frac{91.8}{71.8}[/tex]  

                                         n = 1.27 moles of FeO  

Now solve for x,

                            [tex]x = \frac{2 x 1.27}{71.8}[/tex]

                             x = 0.85 moles

These are just moles of Aluminium that we need to react with FeO, so to find Grams of Aluminium we need,

                                Mass = moles x molecular mass

                                Mass = 0.85 x 27(atomic mass of Al)

                                Mass = 22.86 grams of aluminium is what we need

The heat energy needed to change the temperature of  4.37 gram of silver sample of specific heat 0.24 J/ g °C from a temperature of 25 to 27.5 °C is 2.6 J.

Calorimetry is an analytical  technique used to determine the heat energy absorbed or released by  a system. The calorimetric equation relating the heat energy q with the mass of the substance m, specific heat c and temperature difference ΔT is given as:

q = m c ΔT.

Given that the mass of the sample of iron = 20 g

temperature difference   ΔT = 27.5 - 25 = 2.5 °C

specific heat c = 0.24J/ g °C.

The heat energy absorbed by the sample is calculated as follows:

q = 4.37 g ×  0.24 J/ g °C × 2.5 °C

 = 2.6 J.

Therefore, the heat energy required to the raise the temperature of the sample of iron is 2.6 J.

Find more on calorimetry :

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Answer:sedimentary

Explanation:

Answer:Within the flower, sperm cells are produced by pollen at the tips of stamens, while egg cells develop in ovules, tiny structures embedded in the ovary at the base of the pistil.

I didn't realize the person up top had the same answer give them the brainliest! :)

Answer:

8.7g/mL

Explanation:

I used the density formula to solve. d=m/v= 20g/2.3mL

Answer:

8.7 g/ml

Explanation:

the formula for density is D = M/V

Answer:

Either D or C. I'm so sorry if I got you the wrong answer

Answer:

c

Explanation:

Answer:

the mean is 6 but you don't have that as an option.

Explanation:

the mean is the average.

to find the mean you have to add all of your data first

3 + 2 + 2 + 12 + 6 + 5 + 14 + 4 = 48

then you have to divide your answer by how many numbers there are in total.

48 / 8 = 6

the mean is 6.

Answer:

Bromin-79

Explanation:

The isotope bromine-79 will contain 35 protons, 35 electrons and 44 neutrons.

Answer:

3 elements

Explanation:

The elements are:

- Chromium

- Hydrogen

- Oxygen

Answer:

Hydrogen.

Explanation:

You've probably seen "[tex]H_{2}0[/tex]" which is the formula for water. It means that there's 2 hydrogen atoms, and one oxygen atom, in one molecule of water.

Hope this helps! Feel free to mark me Brainliest if you feel this helped. :)

Answer:

the answer is H. (hydrogen)

Answer:

Recall the colligative properties of freezing point depression and boiling point elevation.

In proportion to the molality product of the solute, (

i

m

), the boiling point will raise and the freezing point will decrease.

Now, consider tap water. You know this!

Is tap water pure water? Of course not! It's a solution of many ions of metals or other inorganic compounds.

Hence, it has a varied boiling and melting point, by definition.

Explanation:

The colligative properties like the boiling point elevation and freezing point depression depend on the solute concentration. The boiling point of the water will increase while the freezing point will decrease.

Colligative properties are the attributes that depend on the amount or the solute concentration rather than on the type or identity of the solute particle. They include freezing point depression, lowering of vapor pressure, osmotic pressure, and boiling point elevation.

The boiling point elevation is the increase of the solvent's boiling point by the addition of the solute. Potassium chloride​ is a salt and a non-volatile solute that increases the boiling point of the solution.

The freezing point depression is one of the colligative properties that states the direct relationship between the molality and the freezing point of the solvent. As potassium chloride is a non-volatile solute it decreases the freezing point of the substance.

Therefore, the boiling point will increase but the freezing point will decrease after the addition of potassium chloride.

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the answer is: 9.80665

Answer:

Scatter plot

Explanation:

Because the plot is scattered all over the place

Answer:

–215 °C

Explanation:

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

Mass of Ne = 10.5 g

Volume (V) = 2.50 L

Pressure (P) = 1 atm

Temperature (T) =?

Next, we shall determine the number of mole present in 10.5 gof Neon, Ne. This can be obtained as follow:

Mass of Ne = 10.5 g

Molar mass of Ne = 20 g/mol

Mole of Ne =.?

Mole = mass /Molar mass

Mole of Ne = 10.5 / 20

Mole of Ne = 0.525 mole

Next, we shall determine the temperature of the sample of Neon, Ne. This can be obtained as follow:

Volume (V) = 2.50 L

Pressure (P) = 1 atm

Number of mole (n) = 0.525 mole

Gas constant (R) = 0.0821 atm.L/Kmol

Temperature (T) =?

PV = nRT

1 × 2.5 = 0.525 × 0.0821 × T

2.5 = 0.525 × 0.0821 × T

Divide both side by 0.525 × 0.0821

T = 2.5 / (0.525 × 0.0821)

T = 58 K

Finally, we shall convert 58 K to degree celsius (°C). This can be obtained as follow:

T(°C) = T(K) – 273

T(K) = 58 K

T(°C) = 58 – 273

T(°C) = –215 °C

Thus, the temperature of the sample of Neon gas is –215 °C.

Answer:

6 grains

Explanation:

The equation of the reaction between NaOH and aspirin is;

C9H8O4(aq) + NaOH (aq) ------>C9H7O4Na(aq) + H2O(l)

Amount of NaOH reacted = concentration × volume = 0.1466 M × 14.40/1000 L = 2.11 × 10^-3 moles

Given that aspirin and NaOH react in a mole ratio of 1:1 from the balanced reaction equation above, the number of moles of aspirin reacted is 2.11 × 10^-3 moles

Hence mass of aspirin reacted = 2.11 × 10^-3 moles × 180.2 g/mol = 0.38 g

If 1 grain = 0.0648 g

x grains = 0.38 g

x= 0.38 g/0.0648 g

x= 6 grains

Answer: C

Explanation: I looked it up lol

Answer:

b?

Explanation:

The answer is C: Radiant energy from the sun travels through the glass, is absorbed by the black pot, and reflected by the aluminum foil.

Answer:

Difference between Contact and Non-Contact Forces

There is no field linked with the contact force. There is always a field linked with non-contact force. The frictional force is an example of a contact force. Gravitational force is an example of a non-contact force.

Explanation:

And it is physics not chem.

Hope this helps u

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Answer:

Mass of hydrogen produced is 0.07g.

Explanation:

Given data:

Mass of magnesium = 7.73 g

Mass of water = 1.31 g

Reaction yield = 88.2%

Mass of hydrogen produced = ?

Solution:

Chemical equation:

Mg + 2H₂O     →   Mg(OH)₂ + H₂

Number of moles of water:

Number of moles = mass/ molar mass

Number of moles = 1.31 g / 18 g/mol

Number of moles = 0.07 mol

Number of moles of magnesium:

Number of moles = mass/ molar mass

Number of moles = 7.73 g / 18 g/mol

Number of moles = 0.43 mol

Now we will compare the moles of water and magnesium with hydrogen.

                    Mg            :           H₂

                     1               :            1

                    0.43          :          0.43

                    H₂O          :             H₂

                      2             :              1

                   0.07           :            1/2×0.07 = 0.035

Mass of hydrogen:

Mass = number of moles × molar mass

Mass = 0.035 mol × 2 g/mol

Mass = 0.07  g

Answer: 0.064 grams is the answer

Explanation:

at the end you must multiply 88.2/100*0.073=0.064