All categories

2 years ago

Help me plsss yall??????

Chemistry

2 answers:

BartSMP [9]2 years ago

3 0

Answer:

First one answer is physical and other remaning chemical

Marat540 [252]2 years ago

3 0

Answer:

Hydrogen is a colorless, tasteless, and odorless gas.

physical

--------------------------------------------------------------------------------------------------------------

Hydrogen is very combustible in the presence of oxygen.

chemical

--------------------------------------------------------------------------------------------------------------

Hydrogen is very reactive with most elements.

chemical

--------------------------------------------------------------------------------------------------------------

Hydrogen is the least dense of all elements.

physical

You might be interested in

ANSWER ASAP (20 POINTS)

SIZIF [17.4K]

Answer:

a chemical formula

Explanation:

5 0

3 years ago

The combustion of ethene in the presence of excess oxygen yields carbon dioxide and water: c2h4 (g) + 3o2 (g) → 2co2 (g) + 2h2o

meriva

Answer:

$\boxed{-267.5}$

Explanation:

You can calculate the entropy change of a reaction by using the standard molar entropies of reactants and products.

The formula is

$\Delta_{r} S^{\circ} = \sum_n {nS_{\text{products}}^{\circ} - \sum_{m} {mS_{\text{reactants}}^{\circ}}}$

The equation for the reaction is

C₂H₄(g) + 3O₂(g) ⟶ 2CO₂(g) + 2H₂O(ℓ)

ΔS°/J·K⁻¹mol⁻¹ 219.5 205.0 213.6 69.9

$\Delta_{r} S^{\circ} = (2\times213.6 + 2\times69.9) - (1\times219.5 + 3\times205.0)\\\\= 567.0 - 834.5 = \boxed{-267.5 \text{ J}\cdot\text{K}^{-1} \text{mol}^{-1}}$

3 0

3 years ago

Which of the following is NOT an allotrope of carbon? A. graphite B. carbon-13 C. a diamond D. a fullerene

egoroff_w [7]

B. carbon-13 is not an allotrope of Carbon.
Allotropes<span> are elements on the periodic table that have more than one crystalline form. </span>Isotopes<span> are atoms of the same element with the same atomic number but have a different mass number.
C-13 is an isotope of carbon, not an allotrope.</span>

5 0

3 years ago

which factor is most responsible for the fact that water is a liquid rather than a gas at room temperature

frosja888 [35]

The answer is Hydrogyn bonding. It keeps the water molocules bonded together and in a liquid state, without it it'd be in a gashious state.

5 0

3 years ago

Read 2 more answers

Your apple juice has a molarity of 3.4 M and a volume of 0.895 litres. What does a student have to do to decrease the molarity t

Jlenok [28]

Answer:

4.285 L of water must be added.

Explanation:

Hello there!

In this case, for this dilution-like problems, we need to figure out the final volume of the resulting solution so that we would be able to obtain the correct volume of diluent (water) to be added. In such a way, we can obtain the final volume, V2, as shown below:

$M_1V_1=M_2V_2\\\\V_2=\frac{M_1V_1}{M_2}$

Thus, by plugging in the initial molarity, initial volume and final molarity (0.587 M) we obtain:

$V_2=\frac{3.4M*0.895 L}{0.587M}\\\\V_2=5.18L$

It means we need to add:

$V_{H_2O} ^{added}=5.18L-0.895L=4.285L$

Of diluent water.

Regards!

6 0

2 years ago