The same baseball is thrown two different times The second throw is faster than the first throw.Which has more kinetic energy?

Sodium hydroxide reacts with aluminum and water to produce hydrogen gas: 2 Al(s) + 2 NaOH(aq) + 6 H2O(l) → 2 NaAl(OH)4(aq) + 3 H

lianna [129]

Answer:

The mass of hydrogen gas formed is 0.205 grams

Explanation:

Step 1: Data given

Mass of 1.83 grams of Al

Mass of NaOH = 4.30 grams

Molar mass of Al = 26.98 g/mol

Molar mass of NaOH = 40 g/mol

Step 2: The balanced equation:

2 Al(s) + 2 NaOH(aq) + 6 H2O(l) → 2 NaAl(OH)4(aq) + 3 H2(g)

Step 3: Calculate moles of Al

Moles Al = mass Al / Molar mass Al

Moles Al = 1.83 grams / 26.98 g/mol

Moles Al = 0.0678 moles

Step 4: Calculate moles of NaOH

Moles NaOH = 4.30 grams / 40 g/mol

Moles NaOH = 0.1075 moles

Step 5: Calculate limiting reactant

For 2 moles of Al, we need 2 moles of NaOH

Aluminium is the limiting reactant. It will completely be consumed ( 0.0678 moles)

NaOH is in excess. There will react 0.0678 moles

There will remain 0.1075 - 0.0678 = 0.0397 moles

Step 6: Calculate moles of hydrogen

For 2 moles of Al, we need 2 moles of NaOH, to produce 3 moles of hydrogen

For 0.0678 moles of Al, there is produced 0.0678 *3/2 = 0.1017 moles of H2

Step 7: Calculate mass of H2

Mass of H2 = Moles H2 * Molar mass of H2

Mass of H2 = 0.1017 moles * 2.02 g/mol

Mass of H2 = 0.205 grams

The mass of hydrogen gas formed is 0.205 grams

6 0

3 years ago

Explain why an indicator is used in titration

stellarik [79]

Answer:

Titrations. Because a noticeable pH change occurs near the equivalence point of acid-base titrations, an indicator can be used to signal the end of a titration. When selecting an indicator for acid-base titrations, choose an indicator whose pH range falls within the pH change of the reaction.

Hope it helped!!

4 0

3 years ago

Round 0.0011675cg to four significant figures

atroni [7]

Answer:

answer is 0.001168 is correct

8 0

3 years ago

Which statements describe the six elements found in all living things? Check all that apply.

vovangra [49]

Answer:

Carbon is the basis of all living things

Nitrogen is found in certain foods

Oxygen and hydrogen combine with each other to form water

Carbon, oxygen, hydrogen, nitrogen, phosphorus and sulfur are found in organic compounds

Explanation:

We are all made up of mainly three elements, Carbon, Hydrogen, and Oxygen. These three elements are found in every living organism on our planet, and along with a few trace elements, they make up all the nutrients we take in and use to build our bodies and survive.

Nitrogen is primarily found in meats, and this is because nitrogen is a key element in amino acids (which are used to build proteins), however we cannot directly assimilate nitrogen from the air, so we have to assimilate it through amino acids already synthesized in plants, or in proteins found in meat.

The chemical formula for water is H₂O. Seeing the chemical formula, it is obvious that hydrogen and oxygen are the only elements in the water molecule.

In our bodies, we use phosphorus to form our skeleton and help maintain it, sulfur and nitrogen can be found in some amino acids, and carbon, hydrogen and oxygen can be found in carbohydrates, lipids and proteins.

3 0

3 years ago

Read 2 more answers

Atoms become excited when they are heated by a flame. How do atoms return from an excited state to a ground state?

ohaa [14]

Atoms return to their ground state by emitting a photon of light.

8 0

3 years ago