If the statement is true, select True. If it is false, select False.

Why does temperature increase with altitude through the stratosphere?

KIM [24]

Answer:

The air molecules are closer together in the upper stratosphere.

Explanation:

8 0

4 years ago

If a compound has a composition of 82% nitrogen and 18% hydrogen, what is the empirical formula for this compound

Damm [24]

Answer: The empirical formula for the given compound is $NH_3$

Explanation : Given,

Percentage of H = 18 %

Percentage of N = 82 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of H = 18 g

Mass of N = 82 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{18g}{1g/mole}=18moles$

Moles of Nitrogen = $\frac{\text{Given mass of nitrogen}}{\text{Molar mass of nitrogen}}=\frac{82g}{14g/mole}=5.8moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 5.8 moles.

For Hydrogen = $\frac{18}{5.8}=3.10\approx 3$

For Nitrogen = $\frac{5.8}{5.8}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of H : N = 3 : 1

Hence, the empirical formula for the given compound is $NH_3$

3 0

3 years ago

Classify the reactions as endothermic or exothermic....PLEASE HELP ASAP

elena55 [62]

1) Endothermic reactions:

a) The reaction between ammonium nitrate and water absorbs heat from the surrounding environment.

There are two types of reaction: endothermic reaction (chemical reaction that absorbs more energy than it releases) and exothermic reaction (chemical reaction that releases more energy than it absorbs).

b) Ammonium chloride dissolved in a beaker of water makes the beaker cold.

Dissolving this salt absorbs heat from beaker.

c) Water separates on hydrogen and oxygen when an electric current is run through it.

Electrolysis of water is the decomposition reaction (heat is required), because from one molecule (water) two molecules (hydrogen and oxygen) are produced. Water is separated into two molecules.

2) Exothermic reactions:

a) Three drops of concetrated sulfuric acid added to 100 milliliters in a beaker makes the beaker hot.

Energy is released, beaker absorbs that heat.

b) Uranium atoms are split to produce nuclear energy.

Nuclear energy is released.

c) Methane and oxygen are combined to produce methanol and heat.

Balanced chemical reaction: 2CH₄ + O₂ → 2CH₃OH + heat.

4 0

3 years ago

Perform the following for Part C of this lab:

kaheart [24]

Answer:

a. 0.0110 L

b. 0.0020 L

c. 0.011 mol

d. 5.5 M

e. 0.66 g

f. 33%

Explanation:

There is some info missing. I will use some values to show you the procedure and then you can replace them with your values.

Titrant (NaOH) concentration: 1.0 M

Vinegar volume: 2.0 mL

Initial buret reading (initial NaOH volume): 0.1 mL

Final buret reading (final NaOH volume): 11.1 mL

a. Calculate the volume of NaOH that was added to the vinegar. Convert this volume to liters. Show your work.

The volume of NaOH is the difference between the final and the initial buret reading.

11.1 mL - 0.1 mL = 11.0 mL × (1 L/1000 mL) = 0.0110 L

b. Convert the measured volume of vinegar to liters. Show your work.

2.0 mL × (1 L/1000 mL) = 0.0020 L

c. Calculate the moles of NaOH using the volume and molarity of NaOH. Show your work. moles = molarity x volume

moles = molarity × volume

moles = (1.0 mol/L) × 0.0110 L = 0.011 mol

d. Since the reaction ratio is 1:1, the moles of acetic acid in the vinegar is equal to the moles of NaOH reacted during the titration. Calculate the molarity of the acetic acid in the vinegar. Show your work. molarity = moles / volume

molarity = moles / volume

molarity = 0.011 mol/0.0020 L = 5.5 M

e. Calculate the grams of acetic acid in the vinegar. Show your work. mass = moles x molar mass (g/mol)

mass = moles × molar mass

mass = 0.011 mol × 60.05 g/mol = 0.66 g

f. Assuming that the density of vinegar is very close to 1.0 g/mL, the 2.0 mL sample of vinegar used in the titration should weigh 2.0 g. Use this to calculate the mass % of acetic acid in the vinegar sample. mass % = (mass acetic acid / mass vinegar) * 100%

mass % = (mass acetic acid / mass vinegar) * 100%

mass % = (0.66 g /2.0 g) * 100% = 33%

6 0

3 years ago

Considering only electron density, will the following reaction occur? 327d1 + 327d2 → yes no

Firlakuza [10]

Answer:

The question is not so clear, but there is a similar question that talks about reaction of alkanes with ammonia

Explanation:

The underlying factor dependent on whether alkane will react with ammonia or not is in their bond and reactivity. basically, alkanes are saturated hydrocarbons with a single bond existing between their chains. They are single bonded hydrocarbons and they majorly undergo SUBSTITUTION REACTION WITH HALOGENS

Alkanes are less reactive in this case, if other functional groups are attached or takes place alongside the reaction, the reaction may have a high chances of taking place.

7 0

4 years ago