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4 years ago

HELP TIMED !!!!

Chemistry

2 answers:

Troyanec [42]4 years ago

6 0

Hello there what is the question?

kipiarov [429]4 years ago

3 0

Answer:

Helium is one of the lightest gas that is found to be stored in the interior of the earth's crust. This helium gas is formed from the constant radioactive decay process. During the time of radioactive decay, the radioactive elements decays and give rise to the formation of alpha particles, which are positively charged. When a pair of electrons are combined with these alpha particles then it produces helium atom.

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When the volume of a gas is

Montano1993 [528]

Answer:

$\boxed {\boxed {\sf 232.9 \textdegree C}}$

Explanation:

This question asks us to find the temperature change given a volume change. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula is:

$\frac {V_1}{T_1}= \frac{V_2}{T_2}$

The volume of the gas starts at 250 milliliters and the temperature is 137 °C.

$\frac{250 \ mL}{137 \textdegree C}= \frac{V_2}{T_2}$

The volume of the gas is increased to 425 milliliters, but the temperature is unknown.

$\frac{250 \ mL}{137 \textdegree C}= \frac{425 \ mL}{T_2}$

We are solving for the new temperature, so we must isolate the variable T₂. First, cross multiply. Multiply the first numerator and second denominator, then multiply the first denominator and second numerator.

$250 \ mL * T_2 = 137 \textdegree C * 425 \ mL$

Now the variable is being multiplied by 250 milliliters. The inverse of multiplication is division. Divide both sides of the equation by 250 mL.

$\frac{250 \ mL * T_2}{250 \ mL}=\frac{ 137 \textdegree C * 425 \ mL}{250 \ mL}$

$T_2=\frac{ 137 \textdegree C * 425 \ mL}{250 \ mL}$

The units of milliliters (mL) cancel.

$T_2=\frac{ 137 \textdegree C * 425 }{250 }$

$T_2= \frac{58225}{250} \textdegree C$

$T_2=232.9 \textdegree C$

The temperature changes to <u>232.9 degrees Celsius.</u>

3 0

3 years ago

According to reference table adv-10, which is the strongest reducing agent?

Mumz [18]

Li(s) (answer A)
Li is strongest reducing agent because of the lowest standard reduction potential. when something is oxidized, it reduces another substance, becoming a reducing.Hence Lithium is strongest reducing agent. Reducing agent is stronger when it has a more positive oxidation potential.

3 0

3 years ago

gypsum is insoluble in water. you are asked to purify a sample of gypsum that is contaminated with a soluble salt.

katen-ka-za [31]

Answer:

a. The apparatus required to purify gypsum sample are: Bunsen burner, beaker, Filter Funnel, stirring rod, the filter paper.

b. Gypsum is a sulfate mineral that is made up of calcium sulfate dihydrate. Step-by-step instruction to purify gypsum sample is as follows:

1. Add water to the gypsum sample in a beaker.

2. Use the stirring rod to mix the mixture well.

3. Filter off the excess solid from the mixture using the filter paper and filter funnel.

4. Put the filtered mixture over the bunsen burner and evaporate the excess water from the mixture.

5. Allow the hot liquid to cool down and filter it again through the filter paper to get the pure gypsum.

7 0

3 years ago

The net ionic equation for the reaction between aqueous sulfuric acid and aqueous sodium hydroxide is ________.

Kaylis [27]

Molecular equation:
$H_{2}SO_{4}(aq) + 2NaOH(aq)--\ \textgreater \ Na_{2}SO_{4}(aq) + 2H_{2}O(l)

Complete ionic equation:

2H^{+}+SO_{4}^{2-} + 2Na^{+} +2OH^{-}--\ \textgreater \ 2Na^{+}+SO_{4}^{2-} + 2H_{2}O(l)


Near 2H^{+},SO_{4}^{2-} , 2Na^{+} , OH^{-} 

should be written (aq).

Remove ions that do not change from both sides

2H^{+} + 2OH^{-}=2H_{2}O

Net ionic equation:

H^{+}(aq) + OH^{-}(aq)=H_{2}O(l)

Answer is D.

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8 0

4 years ago

How many moles of hydrogen gas will form 1.35 L of a 2.75 M Hcl solution reacts?

weeeeeb [17]

<span>1.86 moles of hydrogen gas. Since what the HCl is reacting with hasn't been mentioned, I'll assume zine. In that case, the balanced reaction is Zn + 2HCl ==> ZnCl2 + H2 So for every 2 moles of HCl used, 1 mole of hydrogen gas will be generated. So let's figure out how many moles of HCl we have and then divide by 2. Molarity is defined as moles/liter. So a 2.75 M HCl solution has 2.75 moles of HCl per liter. So the total number of moles we have is: 2.75 mole/L * 1.35 L = 3.7125 mol And since we get 1 mole H2 per mole of HCl, we get: 3.7125 mol / 2 = 1.85625 mol Rounding to 3 significant figures gives us 1.86 moles of hydrogen gas.</span>

3 0

3 years ago