All categories

3 years ago

Choose the correct answer:

Chemistry

1 answer:

irinina [24]3 years ago

7 0

Explanation:

elements are found in period 4 in the periodic table

You might be interested in

Give two reasons why people should use petrochemicals wisely.

SSSSS [86.1K]

I. Because they're a limited resource

2 Because they're a cause of carbon pollution.

8 0

2 years ago

A sample of a compound made entirely from copper and oxygen was found to have a total mass of 0.143 g the mass of copper in the

tensa zangetsu [6.8K]

Mass of Oxygen: 0.0159 grams

Moles of Oxygen: 9.94x10^-4

To find the mass of oxygen, subtract the mass of copper from the total mass.

$0.143-0.1271=0.0159$

There are 0.0159 grams of Oxygen.

To find how many moles there are, divide the given amount of oxygen by the molar mass (atomic mass) of oxygen because that mass is the same as one mole of oxygen.

Molar mass of Oxygen: 16.00

$0.0159/16.00=9.94*10^{-4}$

There are 9.94*10^-4 moles of Oxygen.

6 0

1 year ago

Rank the solutions below in order of increasing acidity. (Drag and drop into the appropriate area)

Vladimir79 [104]

Answer:

0.1 M NaOH, 3 M NH3, 0.01 M CH3COOH, 0.01 M H2SO4, 0.1 M HCl

Explanation:

Strong acids are more acids than weak acids. In the same way, strong bases are more basic than weak bases that are in the same concentration.

Then, the more concentrated acid or base will be more acidic or basic.

CH3COOH. Weak acid

NaOH. Strong base

H2SO4. Strong acid

NH3. Weak base.

HCl. Strong acid

The less acid (More basic):

Strong base, weak base, weak acid, diluted strong acid, undiluted strong acid

7 0

3 years ago

Using the molarity equation, calculate how many grams of salt you need in order to make 80ml of a 2M solution (MW = 58.44g/mole)

ollegr [7]

Answer:

9.35g

Explanation:

The molarity equation establishes that:

$\textrm{molarity}=\frac{\textrm{moles of solute}}{\textrm{liters of solution}}$

So, we have information about molarity (2M) and volume (80 ml=0.08 l), with that, we can find the moles of solute:

$\textrm{moles of solute}=\textrm{molarity}*\textrm{liters of solution}$

$\textrm{moles of solute}= 0.08 \textrm{ l} *2\textrm{ M} = 0.16 \textrm{ mol}$

The mathematical equation that establishes the relationship between molar weight, mass and moles is:

$\textrm{molar weight}= \frac{\textrm{mass}}{\textrm{moles}}$

$\textrm{MW}= \frac{\textrm{m}}{\textrm{n}}$

We have MW (58.44g/mole) and n (0.16 mol), and we need to find m (grams of salt needed) to solve the problem:

$\textrm{m} = \textrm{MW * n}= 58.44\frac{\textrm{g}}{\textrm{mol}} * 0.16 \textrm{ mol} = 9.35 \textrm{ g}$

8 0

3 years ago

What does the pudding represent in the plum pudding model of the atom?

dolphi86 [110]

Answer:

the answer is According to this model, the atom is a sphere of positive charge, and negatively charged electrons are embedded in it to balance the total positive charge. The electrons are like plums in a pudding.

Explanation:

4 0

3 years ago

Read 2 more answers