All categories

3 years ago

Substance tha have excess hydroxide ions (OH-) are

1 answer:

6 0

Substances that posses an excess it greater amount of hydroxide ions are considered basic, or alkali like in solution. They would thus showcase properties of a basic substance.

You might be interested in

What is the entropy change for the freezing process of 1 mole of liquid methanol at its freezing temperature (–97.6˚C) and 1 atm

Rudiy27

Answer : The value of change in entropy for freezing process is, -18.07 J/mol.K

Explanation :

Formula used :

$\Delta S=\frac{\Delta H_{freezing}}{T_f}$

where,

$\Delta S$ = change in entropy

$\Delta H_{fus}$ = change in enthalpy of fusion = 3.17 kJ/mol

As we know that:

$\Delta H_{fus}=-\Delta H_{freezing}=-3.17kJ/mol=-3170J/mol$

$T_f$ = freezing point temperature = $-97.6^oC=273+(-97.6)=175.4K$

Now put all the given values in the above formula, we get:

$\Delta S=\frac{\Delta H_{freezing}}{T_m}$

$\Delta S=\frac{-3170J/mol}{175.4K}$

$\Delta S=-18.07J/mol.K$

Therefore, the value of change in entropy for freezing process is, -18.07 J/mol.K

4 0

4 years ago

The meselson-stahl experiment demonstrated that DNA replication is semi conservative in the figure semi conservative replication

Vlad1618 [11]

Answer:

The correct answer will be option-D.

Explanation:

The semi-conservative mode of replication is the common method of replication used by mostly organisms on earth which were demonstrated by the Meselson and Stahl in 1958.

They used the isotopes of the nitrogen which contains extra neuron which makes the nitrogen-heavy and cultured them in bacteria

The experiment concluded that newly replicated double stranded DNA contains one newly synthesized DNA strand which is complementary to another parental strand. Thus new DNA molecule has one parental strand while other newly synthesized strand.

This is best illustrated by the option-D in the figure and therefore is the correct answer.

7 0

4 years ago

Read 2 more answers

A chemical indicator that changes colors depending on the concentration of h+ in the solution is called a

DanielleElmas [232]

Answer is: acid-base indicator or pH indicators.

Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations.
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄). Phenolphthalein is colorless in acidic solutions and pink in basic solutions.
Another example is methyl orange. It is red colour in acidic solutions and yellow colour in basic solutions.

3 0

4 years ago

Is hardness physical or chemical property

Afina-wow [57]

Answer:

The properties of the Hardness are:

Hardness is a physical property

Hardness is indicative of the strength of chemical bonds between elements.

Diamond can scratch quartz Explanation:

6 0

3 years ago

How much energy is required to raise the temperature of 10.6 grams of gaseous neon from

Alona [7]

Answer:

Approximately $1.95 \times 10^{2}\; \rm J$ .

Explanation:

Look up the specific heat of gaseous neon:

$c = 1.03 \; \rm J \cdot g^{-1} \cdot K^{-1}$ .

Calculate the required temperature change:

$\Delta T = (37.9 - 20.0)\; \rm K = 17.9\; \rm K$ .

Let $m$ denote the mass of a sample of specific heat $C$ . Energy required to raise the temperature of this sample by $\Delta T$ :

$Q = c \cdot m \cdot \Delta T$ .

For the neon gas in this question:

$c = 1.03\; \rm J \cdot g^{-1}\cdot K^{-1}$ .
$m = 10.6\; \rm g$ .
$\Delta T = (37.9 - 20.0)\; \rm K = 17.9\; \rm K$ .

Calculate the energy associated with this temperature change:

$\begin{aligned}Q &= c \cdot m \cdot \Delta T \\ &= 1.03\; \rm J \cdot g^{-1}\cdot K^{-1} \times 10.6\; \rm g \times 17.9\; \rm K \\ &\approx 1.95 \times 10^{2}\; \rm J\end{aligned}$ .

3 0

3 years ago