Ask question

Ask question

All categories

3 years ago

13

In heating and melting curves, what is the name of the heat associated with the solid-liquid phase? A. Heat of formation B. Heat

of fusion C. Heat of sublimation D. Heat of vaporization

1 answer:

Otrada [13]3 years ago

6 0

Answer:

C I believe not quite sure tho

You might be interested in

On the basis of electronegativity, which of these pairs of elements is most likely to form polyatomic ions?

Vinvika [58]

Correct Answer: <span>O and P

Reason:
The nature of bond depends on the electronegativity difference of constituent atoms. If difference in electronegativity of constituent atoms is more, it will result in ionic bonding. Alternatively, if difference in electronegativity of constituent atoms is less, it will prefer covalent bonding. Further, covalently bonded </span><span>elements are most likely to form polyatomic ions.

In present case, electronegativity difference of O and P is minimum. Hence, they </span><span>are most likely to form polyatomic ions.</span>

7 0

3 years ago

Is the equation for reaction 1 balanced? Explain your reasoning. If the reaction is not balanced, then state how you would balan

sveticcg [70]

Answer:

Reaction is already balanced

Explanation:

The equation in reaction 1 is given as;

CH3COOH + NaHCO3 --> CO2 + H2O + Na+ + CH3COO-

The reaction is already balanced. This is because the umber of atoms of elements in the reactant is equal to that of the products

Carbon

Reactant = 2 + 1 = 3

Product = 2 + 2 = 3

Hydrogen

Reactant = 3 + 1 + 1 = 5

Product = 2 + 3 = 5

Oxygen

Reactant = 2 + 3 = 5

Product = 2 +1 + 2 = 5

Sodium

Reactant = 1

Product = 1

3 0

3 years ago

The flask contains 10.0 mL of HCl and a few drops of phenolphthalein indicator. The buret contains 0.160 M NaOH. It requires 18.

olchik [2.2K]

Answer:

Approximately $0.291\; \rm M$ (rounded to two significant figures.)

Explanation:

The unit of concentration $\rm M$ is the same as $\rm mol \cdot L^{-1}$ (moles per liter.) On the other hand, the volume of both the $\rm NaOH$ solution and the original $\rm HCl$ solution here are in milliliters. Convert these two volumes to liters:

$V(\mathrm{NaOH}) = 18.2\; \rm mL = 18.2 \times 10^{-3}\; \rm L = 0.0182\; \rm L$ .
$V(\text{$\mathrm{HCl}$, original}) = 10.0\; \rm mL = 10.0\times 10^{-3}\; \rm L = 0.0100\; \rm L$ .

Calculate the number of moles of $\rm NaOH$ in that $0.0182\; \rm L$ of $0.160\; \rm M$ solution:

$\begin{aligned} n(\mathrm{NaOH}) &= c(\mathrm{NaOH})\cdot V(\mathrm{NaOH})\\ &= 0.160\; \rm mol \cdot L^{-1} \times 0.0182\; \rm L \approx 0.00291\; \rm mol\end{aligned}$ .

$\rm HCl$ reacts with $\rm NaOH$ at a one-to-one ratio:

$\rm HCl\; (aq) + NaOH\; (aq) \to NaCl\; (aq) + H_2O\; (l)$ .

Coefficient ratio:

$\displaystyle \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} = 1$ .

In other words, one mole of $\rm NaOH$ would neutralize exactly one mole of $\rm HCl$ . In this titration, $0.291\; \rm mol$ of $\rm NaOH\!$ was required. Therefore, the same amount of $\rm HC$ should be present in the original solution:

$\begin{aligned}&n(\text{$\mathrm{HCl}$, original})\\ &= n(\mathrm{NaOH})\cdot \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} \\ &\approx 0.00291\; \rm mol \times 1 = 0.00291\; \rm mol\end{aligned}$ .

Calculate the concentration of the original $\rm HCl$ solution:

$\displaystyle c(\text{$\mathrm{HCl}$, original}) = \frac{n(\text{$\mathrm{HCl}$, original})}{V(\text{$\mathrm{HCl}$, original})} \approx \frac{0.00291\; \rm mol}{0.0100\; \rm L} \approx 0.291\; \rm M$ .

5 0

3 years ago

Name this compound please

jasenka [17]

Answer:

Ethanol

Explanation:

2 C atoms and a single OH group.

Formula: C2H5OH

4 0

3 years ago

Zoom all the way in to Daphne Major. Describe its appearance in two sentences.

kicyunya [14]

The Daphne Major is located in the Colon Archipelago. It has a crater composed of volcanic rocks. These rocks are made up from volcanic ashes which hardened over time. The volcano is shaped like a cone which is surrounded by trees and houses several rare birds.

3 0

3 years ago

Read 2 more answers