Examine the system of equations.<br> y = 4x +8,<br> y = 4x-1

a certain country, pivate enterprises provide various goods and services But the govemment provides tree public transportation a

puteri [66]

Mixed economy. Wherever the private and public sector have an active role, they are determined to be a mixed economy.

8 0

3 years ago

Which statement correctly relates two substances from this reaction?

Marta_Voda [28]

We have to know which two substances are related correctly.

The correct answer is: (C) H₃O⁺ is the conjugate acid of H₂O.

In an acid-base reaction, an acid reacts with a base and gives a conjugate base and conjugate acid. The reaction is shown below:

Acid₁ + Base₂ ⇄ Conjugate Base₁ + Conjugate Acid₂

In the reaction H₂CO₃ + H₂O ⇌ H₃O⁺ + HCO₃⁻, H₂CO₃ is an acid because it releases H⁺ ion and converts to HCO₃⁻. Here HCO₃⁻ is the conjugate base of H₂CO₃ ( according Arrhenius theory).

H₂O accepts H⁺ ion and is converted to H₃O⁺ , thus H₂O behaves as Bronsted base. So, H₃O⁺ is the conjugate acid of Bronsted base H₂O.

Hence, the correct answer is: (C) H₃O⁺ is the conjugate acid of H₂O.

5 0

4 years ago

PLEASE HELP! this is a science test/quiz I’m pretty sure the answers are on the bottom if not please comment so I can tell you t

bearhunter [10]

ITS NOT LETTING ME PUT THR ANSWER

4 0

3 years ago

When calcium carbonate is heated, it decomposes to produce calcium oxide and carbon dioxide, as shown in the diagram below. How

Vikki [24]

Explanation:

Before we start with any calculation, we need to determine the stoichiometric relationship between the reactants consumed and the products formed. In other words, we need to establish a balanced chemical equation that describes the decomposition of calcium carbonate as shown below.

$\text{CaCO}_{3} \ \ \text{(s)} \ \overset{\Delta}{\longrightarrow} \ \text{CaO} \ \text{(s)} \ + \ \text{CO}_{2} \ \text{(g)}$ ,

where the uppercase delta symbol, $\Delta$ , above the chemical reaction arrow denotes that heat is applied to make the reaction proceed in the direction of the arrow.

To calculate how many moles are there in 4 grams of calcium carbonate, we use the relation

$n \ = \ \displaystyle\frac{m}{M_{r}}$ ,

where $n$ is the number of moles, $m$ is the mass of the chemical substance and $M_{r}$ is the molar mass of the chemical substance. We first need to identify the molar mass of calcium carbonate,

$M_{r} \, [\text{CaCO}_{3}] \ = \ A_{r} \, [\text{Ca}] \ + \ A_{r} \, [\text{C}] \ + \ 3 \, \times \, A_{r} \, [\text{O}] \\ \\ M_{r} \, [\text{CaCO}_{3}] \ = \ 40.078 \ + \ 12.011 \ + \ 3 \, \times \, 15.999 \\ \\ M_{r} \, [\text{CaCO}_{3}] \ = \ 100.086 \ \text{g mol}^{-1}$

Hence,

$n \ = \ \displaystyle\frac{4 \ \text{g}}{100.086 \ \text{g mol}^{-1}} \\ \\ \\ n \ = \ 0.04 \ \text{mol}$ .

We know that, from the balanced chemical equation above, 1 mole of calcium carbonate following decomposition, will theoretically lead to the production of 1 mole of carbon dioxide. Then, if 0.04 moles of calcium carbonate is decomposed, then, 0.04 moles of carbon dioxide is produced.

To convert the number of moles into the mass of carbon dioxide produced, we need to rearrange the formula as follows.

$n \ = \ \displaystyle\frac{m}{M_{r}} \\ \\ \\m \ = \ n \ \times \ {M_{r}}$ .

Thus,

$M_{r} \, [\text{CO}_{2}] \ = \ A_{r} \, [\text{C}] \ + \ 2 \, \times \, A_{r} \, [\text{O}] \\ \\ M_{r} \, [\text{CO}_{2}] \ = \ (12.011 \ + \ 2 \, \times \, 15.999) \ \text{g mol}^{-1} \\ \\ M_{r} \, [\text{CO}_{2}] \ = \ 44.009 \ \text{g mol}^{-1}$