a reaction vessel contains a small piece of magnesium metal and air (20%) of which is oxygen gas. The mixture is ignited and burns with a burst of light and heat, producing solid magneisum oxide. The mass of mgO, however, is less than the initital mass of magnesium and oxygen combined. What loss of mass

Answer:

0.365 m

Explanation:

The definition of molality is:

First we calculate the moles of the solute, LiCl. We do so using its molar mass:

Then we calculate the mass of the solvent, water. We do so using its density:

Finally we calculate the molality of the solution:

Answer:

19 electrons in first group of 4th period element that is potassium K

Explanation:

Answer:

Absolute error in measurement of A = 0.3

Absolute error in measurement of B = 0.3

Explanation:

Absolute error is a measure of the amount of error in a measurement i.e. a measure of how far away a measurement is from a true value or an indication of the uncertainty in a measurement.

The Absolute Error is the difference between the actual and measured value. In formula, the absolute error, Δx is given as:

Δx = |xi – x|,

Where:  xi is the measurement, x is the true value,

| | indicates that only absolute values are taken

In the measurements by the student in the question:

Metal Cylinder A

measured value = 12.4 grams

actual mass of metal cylinder A = 12.7 g

Using the absolute error formula; Δx = |xi – x|

Absolute error in measurement of A = |12.4 - 12.7| = 0.3

Metal Cylinder B

measured value = 75.4 grams

actual mass of metal cylinder B = 75.1 g

Using the absolute error formula; Δx = |xi – x|

Absolute error in measurement of B = |75.4 - 75.1| = 0.3

Answer:

[tex]k_2=2.46[/tex]

Explanation:

Hello!

In this case, according to the Arrhenius equation for variable temperature:

[tex]ln(\frac{k_2}{k_1} )=-\frac{Ea}{R}(\frac{1}{T_2} -\frac{1}{T_1} )[/tex]

Given the temperatures to be computed in kelvins and the activation energy, we obtain:

[tex]ln(\frac{k_2}{0.924} )=-\frac{89800J/mol}{8.314J/(mol*K)}(\frac{1}{306.45K} -\frac{1}{298.15K} )\\\\ln(\frac{k_2}{0.924} )=0.981\\\\k_2=0.924*exp(0.981)\\\\k_2=2.46[/tex]

Best regards!

Answer:

The anwer is not D the anwer is A

Explanation:

Answer:

1H₂  +  1Cl₂  →   2HCl

Explanation:

The reaction that illustrates the law of conservation of mass is shown below:  

         1H₂  +  1Cl₂  →   2HCl

According to the law of conservation of mass "in a chemical reaction, matter is neither created nor destroy but atoms are rearranged".

Therefore, we are expected to the end a reaction with the amount of substance we start with.

 Element                                H                                    Cl

Reactants                               2                                      2

Products                                 2                                      2

We see that number of atoms on both sides are the same.

Answer: Convergent Boundary

Explanation:

Two plates converge at one point

Explanation:

given

kpo4 it has molar mass of 39+31+(16*4)=134

m=n*Mm

m=5.35*134

m=716.9

Answer:

it is he

Explanation:

beacuse Noble gases have 2 volence

Answer: 310.7 grams

Explanation:

Multiply the two values so the units of mL cancel and you get grams

2.545*122.1 = 310.7 grams

Answer: the answer is B

Explanation:

Answer:

The answer should be A. Adding carbon to iron makes it tougher and stronger.

The addition of carbon atom to iron metal, enhances the property of hardness of metal.

Alloy is a compound which is formed by the mixture of two or more than two metals with different properties to make a new compound with better properties.

When we add carbon atom in the iron metal, it deviates the crystal lattice property of iron and makes it more harder. So, the content of carbon in the iron is directly proportional to the hardness of iron metal.

Hence, option (A) is correct i.e. hardness.

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The percent by weight (w/w%) of sugar in soda : 6.216%

Given

mass of sugar = 23 g

total mass = 370 g

Required

the percent weight

Solution

%weight = (mass of solute : mass of solution) x 100%

solute = sugar

solution = solvent + solute = water + sugar

percent weight of sugar in soda :

= (23 : 370) x 100%

= 6.216 %

Explanation:

i think w is the required answer

Answer:

12

Explanation:

The distance that Neil Pogo travels is 16 meters. While the displacement is Zero (0).

Displacement may be defined as the distance traveled by an object from the initial point to the final point. It is a vector quantity and has a direction and magnitude. In a more simple sense, it is known to be the alteration of the position of the object.

According to the question,

The total distance covered by Neil Pogo = 8 m east then 8 m west = 16 meters.

But according to the definition of displacement, his total displacement was zero. This is because the distance between his initial point and the final point is zero.

He returned back to the same place indicating his zero displacements.

Therefore, the distance that Neil Pogo travels is 16 meters. While the displacement is Zero (0).

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Answer:

Potassium is an element that has 19 electrons

Answer:

There are 54.03 grams in 3 moles of H2O

There are 3.2 moles in 519.3 g FeCl3

There are 56.0 g in 2 moles of CO

Explanation:

H2O molar mass: 18.01 g/mol

   to calculate the grams:  3 mol H2O * 18.01 g/mol

FeCl3 molar mass: 162.2 g/mol

   to calculate moles:  519.3g FeCl3 / 162.2 g/mol

CO molar mass: 28.01 g/mol

   to calculate grams: 28.01 g/mol CO * 2 mol CO

Answer:

the flow rate of the gas stream leaving the condenser is 71.9 moles/min

Explanation:    

Given the data in the question and the figure below;

N2 BALANCE

(100% - 18%) × ( mole rate in ) = ( 100% - 5%) × ( mole rate out)

0.82 × ( mole rate in ) = 0.95 × ( mole rate out)

mole rate in = 0.95 × ( mole rate out) / 0.82

mole rate in = 1.1585365853 × ( mole rate out)

now;

HEXANE BALANCE

0.18 × ( mole rate in ) = 0.0500 × ( mole rate out) + condensate  --- equ 1

but condensate = 1.5 L/min × ( density of hexane ) × 1/molar mass of hexane

we know that;

density of hexane is 0.6548 g/mL

and molar mass of hexane is 86.18 g/mol

so,

condensate = 1.5 L/min × ( 0.6548 g/mL × 1000 mL/L ) × ( 1/86.18 g/mol)

condensate = 11.3970758876

now lets substitute into equation 1

0.18 × ( mole rate in ) = 0.0500 × ( mole rate out) + condensate

⇒ 0.18 × ( 1.1585365853 × ( mole rate out) ) = 0.0500 × ( mole rate out) + 11.3970758876

⇒ 0.208536585354(mole rate out) = 0.0500( mole rate out) + 11.3970758876

⇒ 0.208536585354(mole rate out) - 0.0500( mole rate out) = 11.3970758876

⇒ 0.158536585354(mole rate out) = 11.3970758876

mole rate out = 11.3970758876 / 0.158536585354

mole rate out =  71.889247 ≈ 71.9 moles/min

Therefore, the flow rate of the gas stream leaving the condenser is 71.9 moles/min

Answer:

Color change, precipitation, bubbling

Explanation:

Chemical change changes the chemical composition and undergoes a process in which it results as a new substance.

Answer:

4.16 g

Explanation:

Volume,  V = 2.90 L

STP mans standard temperature and pressure

T = 273 K

P = 1 atm

Mass = ?

Using the ideal gas equation;

PV = nRT

where R = General gas constant = 0.082 L atm mol-1 K-1

n = PV / RT

n = 1 * 2.90 /  (0.082 * 273)

n = 2.90 / 22.386

n = 0.130 mol

The relationship between moles and mass;

Mass = number of moles * Molar mass

Mass = 0.130 mol * 32 g/mol

Mass = 4.16 g

Answer:4.14

Explanation:just answered the question

Answer:

MM = 182.13g/mol

Explanation:

Hello!

In this case, since the boiling point elevation is computed via:

[tex]\Delta Tb=i*m*K[/tex]

Thus, since adrenaline is nonionizing, we can compute the molality at first instance:

[tex]m=\frac{\Delta Tb}{i*K}=\frac{0.49K}{1*5.02kg\frac{K}{mol} } \\\\m=0.0976mol/kg[/tex]

Now, we compute the the moles of adrenaline in 360 g (0.360 kg) of CCl4:

[tex]n=0.0976mol/kg*0.360kg\\\\n=0.0351mol[/tex]

Finally, the molar mass:

[tex]MM=\frac{6.4g}{0.0351mol}\\\\MM=182.13g/mol[/tex]

Best regards!

Answer:

Protons are positive, electrons are negative, neutrons have to charge. Most of an Atoms mass comes from its protons and neutrons

Explanation:

I took some notes in my notebook about Atoms.

Answer:

any gas takes up 22.4L per mole so 2.4*22.4=53.76

Explanation:

In 2.4 moles at STP, 53.79 litres of N2 gas are present.

Moles are defined as the amount of substance of a system that contain the same number of entities as the number of atoms in 12g of carbon 12.

STP is defined as the standard temperature and pressure. At STP, as system has s temperature of zero degree centigrade or 273 Kelvin and the pressure is 1 atm.

PV= nRT

P= 1 atm

V= ?

n= 2.4 moles

R= 0.0821 L atm /K/mol

1 x V = 2.4 x 0.0821 x 273

V = 53.79 litres

Hence, 53.79 litres of N2 gas is present in 2.4 moles at STP.

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Answer:

By observing the time between transits, we know the orbital period. Kepler's Third law can be used to determine the orbital radius of the planet if the mass of the orbiting star is known (R3=T2−Mstar/Msun, the radius is in AU and the period is in earth years)

hope this helps you out

Answer:

Magma

Volcanic glass

Granite and pumice

Explanation:

Answer:

Magma,

Volcanic Glass,

Granite and Pumice,

Lava

Explanation:

Answer:

c the car will stop and the person will keep moving forward

Explanation:

Because since the person has no force apllied they will keep moving until force is apllied.

Answer:

Glucose!!

Explanation:

Also keep in mind that the actual sugar produced from photosynthesis is C6H12O6, which is the basis for glucose as well as other complex molecules

Answer:

Glucose

Explanation:

photosynthesis uses the energy from the light to convert carbon dioxide molecules which makes glucose

Answer:

I just umm

Explanation: