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3 years ago

URGENT PLS HELP!!!!!

Chemistry

2 answers:

aksik [14]3 years ago

5 0

Answer:

Explanation:

Elements in group 2A have 2 valence electrons in their outer shell, so when they bond with other atoms, they are most likely to give away these 2 electrons. With 2 electrons gone, the ion will have a positive charge (since there are now more protons than electrons in the atom).

Alex777 [14]3 years ago

3 0

Answer is +2 in the group 2a

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What is the minimum of acetic anhydride (102.1 g/mol) required to react completely with the 2.94 grams of salicylic acid? What v

Lady bird [3.3K]

Answer:

a) the minimun of acetic anhydride required for the reaction is 2.175 g (CH3CO)2O

b) V acetic anhydride = 2.010 mL

Explanation:

balanced reaction:

C6H4OHCOOH + (CH3CO)2O ↔ C9H8O4 + C2H4O2

⇒ mol salicylic acid = 2.94 g C6H4OHCOOH * ( mol C6H4OHCOOH / 138.121 g ) = 0.0213 mol C6H4OHCOOH

⇒ mol acetic anhydride = 0.0213 mol C6H4OHCOOH * ( mol (CH3CO)2O / mol C6H4OHCOOH ) = 0.0213 mol (CHECO)2O

⇒ g acetic anhydride = 0.0213 mol * ( 102.1 g/mol ) = 2.175 g CH3CO)2O

b) V = 2.175 g (CH3CO)2 * ( mL / 1.082 g ) = 2.010 mL (CH3CO)2O

4 0

3 years ago

If 16.00 g of O₂ reacts with 80.00 g NO, how many the excess reactant are left over? (enter only the value, round to whole numbe

pishuonlain [190]

Answer:

Explanation:

We will need a balanced equation with masses, moles, and molar masses of the compounds involved.

1. Gather all the information in one place with molar masses above the formulas and masses below them.

Mᵣ: 30.01 32.00 46.01

2NO + O₂ ⟶ 2NO₂

Mass/g: 80.00 16.00

2. Calculate the moles of each reactant

$\text{moles of NO} = \text{80.00 g NO} \times \dfrac{\text{1 mol NO}}{\text{30.01 g NO}} = \text{2.666 mol NO}\\\\\text{moles of O}_{2} = \text{16.00 g O}_{2} \times \dfrac{\text{1 mol O}_{2}}{\text{32.00 g O}_{2}} = \text{0.5000 mol O}_{2}$

3. Calculate the moles of NO₂ we can obtain from each reactant

From NO:

The molar ratio is 2 mol NO₂:2 mol NO

$\text{Moles of NO}_{2} = \text{2.333 mol NO} \times \dfrac{\text{2 mol NO}_{2}}{\text{2 mol NO}} = \text{2.333 mol NO}_{2}$

From O₂:

The molar ratio is 2 mol NO₂:1 mol O₂

$\text{Moles of NO}_{2} = \text{0.5000 mol O}_{2}\times \dfrac{\text{2 mol NO}_{2}}{\text{1 mol Cl}_{2}} = \text{1.000 mol NO}_{2}$

4. Identify the limiting and excess reactants

The limiting reactant is O₂ because it gives the smaller amount of NO₂.

The excess reactant is NO.

5. Mass of excess reactant

(a) Moles of NO reacted

The molar ratio is 2 mol NO:1 mol O₂

$\text{Moles reacted} = \text{0.500 mol O}_{2} \times \dfrac{\text{2 mol NO}}{\text{1 mol O}_{2}} = \text{1.000 mol NO}$

(b) Mass of NO reacted

$\text{Mass reacted} = \text{1.000 mol NO} \times \dfrac{\text{30.01 g NO}}{\text{1 mol NO}} = \text{30.01 g NO}$

(c) Mass of NO remaining

Mass remaining = original mass – mass reacted = (80.00 - 30.01) g = 50 g NO

5 0

3 years ago

Logs in a fire, and charged batteries are examples of?

vlabodo [156]

Answer:

Logs in a fire is an example of something burning, also changing its state of form. I think thats chemical change; going from wood to ashes. And charged batteries means they haven't been used yet or they were just charged, resulting in physical change.

Explanation:

I just learned this in science.

I hope this helps!

7 0

4 years ago

The lac repressor protein binds to the operator when it is _____.

Thepotemich [5.8K]

The lac repressor protein binds to the operator when it is active. The lac repressor is a protein or a DNA-bounding protein as it is called. The lac repressor also involves the lactose metabolism and it is also responsible for the transcription of three lac genes.

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3 years ago

Convert 150.0 g to mg.

tatyana61 [14]

There are 1000 milligrams in a gram, so you can find the answer through multiplication: 150 • 1000

The answer is 150,000

6 0

4 years ago