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2 years ago

HELP ASAP AND ILL GIVE U BRAINLIEST

1 answer:

5 0

Definition-the quantity of matter that a body contains, as measured by its acceleration under a given force or by the force exerted on it by a gravitational field (in general use) weight.

c. It is the amount of matter in the object.

Hope this helps.

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Is the tendency of copper to turn green when exposed to air chemical or physical property?

Zielflug [23.3K]

Chemical. The copper atoms form new chemical bonds with atoms in the air.

8 0

2 years ago

9A. A sample of hydrogen at 1.56 atm had it's pressure decreased to 0.73

densk [106]

Answer:

351.43mL

Explanation:

To calculate the original volume of hydrogen gas in this question, the Boyle's law equation will be used. Boyle's law equation is:

P1V1 = P2V2

Where; P1 = initial pressure

V1 = initial volume

P2 = final pressure

V2 = final volume

According to this question, the P1= 1.56atm, V1 = ?, P2 = 0.73atm, V2 = 751mL

Hence;

P1V1 = P2V2

1.56 × V1 = 0.73 × 751

1.56 V1 = 548.23

V1 = 548.23/1.56

V1 = 351.43mL

Therefore, the original volume of hydrogen gas is 351.43 mL.

4 0

3 years ago

1. Why do scientists use a standard measurement system?

Margaret [11]

Answer:

Explanation:

1.Scientists use a shared system for reporting measurements called the International System of Units (SI). We use common measurement systems because science involves a lot of replication to confirm results. The most common system used in science is the metric system.

2.m, kg, m^3

3. g value change

3 0

2 years ago

Read 2 more answers

PLEASE HELP!!!

NNADVOKAT [17]

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Investigators do not need a warrant for analyzing crime scenes due to the fact of the dangers of the fire. You must work quickly because accelerants tend to evaporate within days, sometimes hours. It is also important to note that finding the origin of the fire is very important, to make sure it won't be reignited. Debris is usually cleaned away quickly to ensure health and safety issues.

The point of origin of a fire is the lowest point, since fire burns upwards.

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Low explosive: decompose slowly and include black and smokeless powder. They are the most common type of explosives, and are readily available.

4 0

2 years ago

If 8.50 g of phosphorus reacts with hydrogen gas at 2.00 atm in a 10.0-L container at 298 K, calculate the moles of PH3 produced

ahrayia [7]

Answer:

The moles of PH₃ produced are 0.2742 and the total number of moles of gas present at the end of the reaction is 0.6809.

Explanation:

Phosphorus reacts with H₂ according to the balanced equation:

P₄ (s) + 6 H₂ (g) ⇒ 4 PH₃ (g)

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:

P₄: 1 mole
H₂: 6 moles
PH₃:4 moles

Being the molar mass of the compounds:

P₄: 124 g/mole
H₂: 2 g/mole
PH₃: 34 g/mole

The following mass amounts of each compound participate in the reaction:

P₄: 1 mole* 124 g/mole= 124 g
H₂: 6 mole* 2 g/mole= 12 g
PH₃: 4 moles* 34 g/mole= 136 g

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:

P * V = n * R * T

In this case you know:

P= 2 atm
V= 10 L
n= ?
R= 0.082 $\frac{atm*L}{mol*K}$
T= 298 K

Replacing:

2 atm*10 L= n*0.082 $\frac{atm*L}{mol*K}$ *298 K

and solving you get:

$n=\frac{2 atm*10 L}{0.082\frac{atm*L}{mol*K}*298 K }$

n=0.818 moles

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

To determine the limiting reagent, you can use a simple rule of three as follows: if 6 moles of H₂ react with 124 g of P₄, 0.818 moles of H₂ with how much mass of P₄ will it react?

$mass of P_{4}=\frac{0.818 moles of H_{2}*124 grams of P_{4}}{6 moles of H_{2}}$

mass of P₄= 16.90 grams

But 16.90 grams of P₄ are not available, 8.50 grams are available. Since you have less mass than you need to react with 0.818 moles of H₂, phosphorus P₄ will be the limiting reagent.

Then you can apply the following rules of three:

If 124 grams of P₄ produce 4 moles of PH₃, 8.50 grams of P₄, how many moles do they produce?

$moles of PH_{3} =\frac{8.5 grams of P_{4}*4 moles of PH_{3} }{124grams of P_{4}}$

moles of PH₃=0.2742

If 124 grams of P₄ react with 6 moles of H₂, 8.50 grams of P₄ with how many moles of H₂ do they react?

$moles of H_{2} =\frac{8.5 grams of P_{4}*6 moles of H_{2} }{124grams of P_{4}}$

moles of H₂= 0.4113

If you have 0.818 moles of H₂, the number of moles of gas H₂ present at the end of the reaction is calculated as:

0.818 - 0.4113= 0.4067

Then the total number of moles of gas present at the end of the reaction will be the sum of the moles of PH₃ gas and H₂ gas that did not react:

0.2742 + 0.4067= 0.6809

Finally, the moles of PH₃ produced are 0.2742 and the total number of moles of gas present at the end of the reaction is 0.6809.

5 0

2 years ago