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4 years ago

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Which of the following precautions is important when using a Bunsen burner or Meker burner?a. Set up your work space so that wir

es and cables cannot accidentally make contact with the flame or hot glassware and meltb. Set up your work space with the burner in a secure location away from the edge of the benchc. Set up the work space so that flammable materials are away from the burnerd. Never leave an open flame unattendede. Remember that any glassware heated by the burner will look the same when hot as cold, and it will take a while to coolf. Always tie back hair

1 answer:

Gekata [30.6K]4 years ago

6 0

Answer:

Never leave an open flame unattended

Explanation: if an open flame is left unattended it can cause a fire outbreak so we have to watch it at all times to prevent the fire outbreak

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The pressure inside a compressed gas cylinder is 144 atm at 48°C. What will the pressure inside the cylinder be after it is cool

Andrews [41]

<h3>Answer:</h3>

134 atm

<h3>Explanation:</h3>

Based on the pressure law, the pressure of a gas varies directly proportionally to the absolute temperature at a constant volume.

Therefore; we are going to use the equation;

$\frac{P1}{T1}=\frac{P2}{T2}$

In this case;

Initial pressure, P1 = 144 atm

Initial temperature, T1 (48°C) = 321 K

Final temperature, T2 (25°C) = 298 K

We need to find the final pressure,

Therefore;

P2 = (P1/T1)T2

= (144/321)× 298 K

= 133.68 atm

= 134 atm

Therefore, the new pressure will be 134 atm.

5 0

4 years ago

How do you make molecular equations a balanced iconic.

asambeis [7]

<span>First, write the net ionic equation for the unbalanced reaction. If you are given a word equation to balance, you'll need to be able to identify strong electrolytes, weak electrolytes and insoluble compounds. Strong electrolytes completely dissociate into their ions in water. Examples of strong electrolytes are strong acids, strong bases, and soluble salts. Weak electrolytes yield very few ions in solution, so they are represented by their molecular formula (not written as ions). Water, weak acids, and weak bases are examples of weak electrolytes. The pH of a solution can cause them to dissociate, but in those situations, you'll be presented an ionic equation, not a word problem. Insoluble compounds do not dissociate into ions, so they are represented by the molecular formula. A table is provided to help you determine whether or not a chemical is soluble, but it's a good idea to memorize the solubility rules.

</span><span><span>arate the net ionic equation into the two half-reactions. This means identifying and separating the reaction into an oxidation half-reaction and a reduction half-reaction. </span><span>For one of the half-reactions, balance the atoms except for O and H. You want the same number of atoms of each element on each side of the equation. </span><span>Repeat this with the other half-reaction. </span><span>Add H2O to balance the O atoms. Add H+ to balance the H atoms. The atoms (mass) should balance out now. </span><span>Now balance charge. Add e- (electrons) to one side of each half-reaction to balance charge. You may need to multiply the electrons the the two half-reactions to get the charge to balance out. It's fine to change coefficients as long as you change them on both sides of the equation. </span><span>Now, add the two half-reactions together. Inspect the final equation to make sure it is balanced. Electrons on both sides of the ionic equation must cancel out. </span><span>Double-check your work! Make sure there are equal numbers of each type of atom on both sides of the equation. Make sure the overall charge is the same on both sides of the ionic equation. </span><span>If the reaction takes place in a basic solution, add an equal number of OH- as you have H+ ions. Do this for both sides of the equation and combine H+ and OH- ions to form H2O. </span><span>Be sure to indicate the state of each species. Indicate solid with (s), liquid for (l), gas with (g), and aqueous solution with (aq). </span><span>Remember, a balanced net ionic equation only describes chemical species that participate in the reaction. Drop additional substances from the equation.ExampleThe net ionic equation for the reaction you get mixing 1 M HCl and 1 M NaOH is:H+(aq) + OH-(aq) → H2O(l)Even though sodium and chlorine exist in the reaction, the Cl- and Na+ ions are not written in the net ionic equation because they don't participate in the reaction.</span></span>

4 0

3 years ago

Read 2 more answers

Is know as a force that pulls an object weight to center of the earth

vlabodo [156]

That force would be gravity. Gravity is what pulls any object down towards Earth due to the large mass of the Earth.

4 0

3 years ago

Read 2 more answers

When iron metal reacts with sulfuric acid, it produces iron (III) sulfate and hydrogen gas. Balance the equation: Fe + H2SO4 → F

mel-nik [20]

<h3>Answer:</h3>

2Fe(s) + 3H₂SO₄ → Fe₂(SO₄)₃ + 3H₂(g)

<h3>Explanation:</h3>

The equation for the reaction between iron metal and sulfuric acid is given by;

Fe(s) + H₂SO₄ → Fe₂(SO₄)₃ + H₂(g)

We are supposed to balance the equation:

What do we mean by balancing a chemical equation?

Balancing a chemical equations means that we want to make sure the number of atoms of each element is the same on both sides of the equation.

How is balancing done?

Balancing of chemical equations is try and error process that is done by putting appropriate coefficients on the reactants and products to equate the number of atoms of each element.

Why are subscripts on the compounds not changed?

Subscripts in a compound show the actual number of atoms of each element in the compound and therefore can never be altered with because it will distort the chemical compound.

Why is it necessary to balance chemical equations?

Chemical equations are balanced for them to obey the law of conservation of mass.
According to this law, the mass of the reactants should be equal to the mass of products, which is achieved through balancing an equation.

What is the required balanced equation?

The equation given can be balanced by putting the coefficients 2, 3, 1, 3 in that order on the reactants and products.

Therefore, the balanced chemical equation is;

2Fe(s) + 3H₂SO₄ → Fe₂(SO₄)₃ + 3H₂(g)

6 0

3 years ago

Read 2 more answers

If 150 g dimethylhydrazine reacts with excess dinitrogen tetroxide and the product gases are collected at 127oC in an evacuated

zhuklara [117]

Answer : The the partial pressure of the nitrogen gas is 0.981 atm.

The total pressure in the tank is 2.94 atm.

Explanation :

The balanced chemical reaction will be:

$(CH_3)_2N_2H_2(l)+2N_4O_4(l)\rightarrow 3N_2(g)+4H_2O(g)+2CO_2(g)$

First we have to calculate the moles of dimethylhydrazine.

Mass of dimethylhydrazine = 150 g

Molar mass of dimethylhydrazine =60.104 g/mole

$\text{Moles of dimethylhydrazine}=\frac{\text{Mass of dimethylhydrazine}}{\text{Molar mass of dimethylhydrazine}}$

$\text{Moles of dimethylhydrazine}=\frac{150g}{60.104g/mole}=2.49mole$

Now we have to calculate the moles of $N_2$ gas.

From the balanced chemical reaction we conclude that,

As, 1 mole of $(CH_3)_2N_2H_2$ react to give 3 moles of $N_2$ gas

So, 2.49 mole of $(CH_3)_2N_2H_2$ react to give $2.49\times 3=7.47$ moles of $N_2$ gas

Now we have to calculate the partial pressure of nitrogen gas.

Using ideal gas equation :

$PV=nRT\\\\P_{N_2}=\frac{nRT}{V}$

where,

P = Pressure of $N_2$ gas = ?

V = Volume of $N_2$ gas = 250 L

n = number of moles $N_2$ gas = 7.47 mole

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of $N_2$ gas = $127^oC=273+127=400K$

Putting values in above equation, we get:

$P_{N_2}=\frac{(7.47mole)\times (0.0821L.atm/mol.K)\times 400K}{250L}=0.981atm$

Thus, the partial pressure of the nitrogen gas is 0.981 atm.

Now we have to calculate the total pressure in the tank.

Formula used :

$P_{N_2}=X_{N_2}\times P_T$

$P_T=\frac{1}{X_{N_2}}\times P_{N_2}$

$P_T=\frac{1}{(\frac{n_{N_2}}{n_T})}\times P_{N_2}$

$P_T=\frac{n_{T}}{n_{N_2}}\times P_{N_2}$

where,

$P_T$ = total pressure = ?

$P_{N_2}$ = partial pressure of nitrogen gas = 0.981 atm

$n_{N_2}$ = moles of nitrogen gas = 3 mole (from the reaction)

$n_{T}$ = total moles of gas = (3+4+2) = 9 mole (from the reaction)

Now put all the given values in the above formula, we get:

$P_T=\frac{9mole}{3mole}\times 0.981atm=2.94atm$

Thus, the total pressure in the tank is 2.94 atm.

8 0

3 years ago