Could someone help me with this. i am very confused.

What is the one variable that is changed in the experimental group called? the placebo the independent variable the control grou

BlackZzzverrR [31]

Answer:

the independant variable

Explanation:

4 0

3 years ago

A sample in the laboratory is found to contain 3.36 grams of hydrogen, 20.00 grams of carbon, and 26.64 grams of oxygen. The mol

KonstantinChe [14]

Answer:

Empirical formula is CH₂O.

Molecular formula = C₆H₁₂O₆

Explanation:

Given data:

Mass of hydrogen = 3.36 g

Mass of carbon = 20.00 g

Mass of oxygen = 26.64 g

Molar mass of compound = 180.156 g/mol

Empirical formula = ?

Molecular formula = ?

Solution:

Empirical formula:

It is the simplest formula gives the ratio of atoms of different elements in small whole number

Number of gram atoms of H = 3.36 / 1.01 = 3.3

Number of gram atoms of O = 26.64 / 16 = 1.7

Number of gram atoms of C = 20 / 12 = 1.7

Atomic ratio:

C : H : O

1.7/1.7 : 3.3/1.7 : 1.7/1.7

1 : 2 : 1

C : H : O = 1 : 2 : 1

Empirical formula is CH₂O.

Molecular formula:

Molecular formula = n (empirical formula)

n = molar mass of compound / empirical formula mass

Empirical formula mass = CH₂O = 12×1 + 2× + 16

Empirical formula mass = 30

n = 180.156 / 30

n = 6

Molecular formula = n (empirical formula)

Molecular formula = 6 (CH₂O)

Molecular formula = C₆H₁₂O₆

5 0

3 years ago

Forces between similar molecules are said to be

podryga [215]

Answer:

Forces between similar molecules are said to be cohesive while those between different types of molecules are said to be adhesive.

Water 'beads' due to its strong cohesive forces. The meniscus of water in a glass tube is concave because the adhesive forces are strong.

Explanation:

The water in a tube has stronger adhesive forces between the water and glass molecules, so the cohesive forces between water molecules are weaker. That makes the water 'ascend' through the tube, giving a concave form of the meniscus. Another example is mercury, which is the opposite. In this case, the cohesive forces are stronger than the adhesive ones, thus the meniscus is convex.

4 0

3 years ago

Classify the following as either solutions or colloids. If a colloid, name the type of colloid and identify both the dispersed a

aev [14]

Answer:

a. glucose in water( solution)

b. smoke in air (colloids)

c. carbon dioxide in air (solution)

d. milk( colloids)

Explanation:

A solution is said to be formed when a solute dissolves in a solvent to form a homogeneous mixture. The solute particles are less than 10^-9m in size. Familiar solutions are those where the solute are dissolved in a liquid solvent. When the liquid water, the solution is known as an aqueous solution. A typical example is (glucose in water). In some other cases, the apparent solution of a solute in a solvent is accompanied by a chemical reaction and this is often known as a chemical reaction. A typical example is (carbon dioxide in air).

Colloids are also known as false solutions. Here, the individual solute particles are larger than the particles of the true solution, but not large enough to be seen by the naked eye. When a light beam is placed beside a beaker containing a colloid, the light rays of the beam can be clearly seen. This shows that it exhibits the Tyndall effect while a solution dosent exhibit such.

In a colloid, the liquid solvent is more appropriately know as the DISPERSION medium while the solid solute particles constitute the DISPERSED substance. This can either be solid, liquid or gas.

For example:

--> smoke in air : Dispersion medium is gas while the dispersed substance is solid.

--> milk: Dispersion medium is liquid while the dispersed substance is liquid.

7 0

3 years ago

Where does a mid ocean ridge form?

Anit [1.1K]

There are divergent boundaries where the plates are moving away from each other, causing magma to rise up. The boiling lava is almost immediately cooled and forms new sea floor crust.

8 0

3 years ago