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3 years ago

Which statement is true of a catalyst?

Chemistry

1 answer:

chubhunter [2.5K]3 years ago

6 0

Answer:

Correct option is D.

It accelerates the reaction rates of a mixture.

Explanation:

It is used to speed up a reaction by lowering the activation energy.Catalysis is the backbone of many industrial processes, which use chemical reactions to turn raw materials into useful products.

Types

There are two types of catalyst (1) Homogeneous (2) Heterogeneous

In a heterogeneous reaction, the catalyst is in a different phase from the reactants. In a homogeneous reaction, the catalyst is in the same phase as the reactants.

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What product of an acid base reaction is an ionic compound apex?

charle [14.2K]

When acids react with bases they produce salt and water such as:
HCl + NaOH → NaCl + H₂O
According to strength of acid and base, we have 4 types of salts:
salt of strong acid and strong base like: NaCl
salt of weak acid and strong base like: CH₃COONa
salt of strong acid and weak base like: NH₄Cl
salt of weak acid and weak base like: CH₃COONH₄

8 0

3 years ago

Read 2 more answers

In Part III, the phenolphthalein indicator is used to monitor the equilibrium shifts of the ammonia/ammonium ion system. The phe

AnnZ [28]

The pink color in the solution fades. Some of the colored indicator ion converts to the colorless indicator molecule.

<h3>Explanation</h3>

What's the initial color of the solution?

$\text{NH}_4\text{Cl}$ is a salt soluble in water. $\text{NH}_4\text{Cl}$ dissociates into ions completely when dissolved.

$\text{NH}_4\text{Cl} \; (aq)\to {\text{NH}_4}^{+} \; (aq) +{\text{Cl}}^{-} \; (aq)$ .

The first test tube used to contain $\text{NH}_4\text{OH}$ . $\text{NH}_4\text{OH}$ is a weak base that dissociates partially in water.

$\text{NH}_4\text{OH} \; (aq) \rightleftharpoons {\text{NH}_4}^{+} \;(aq)+ {\text{OH}}^{-} \; (aq)$ .

There's also an equilibrium between $\text{OH}^{-}$ and ${\text{H}_3\text{O}}^{+}$ ions.

${\text{OH}}^{-}\;(aq) + {\text{H}_3\text{O}}^{+} \;(aq) \to 2\; \text{H}_2\text{O} \;(l)$ .

$\text{OH}^{-}$ ions from $\text{NH}_4\text{OH}$ will shift the equilibrium between $\text{OH}^{-}$ and ${\text{H}_3\text{O}}^{+}$ to the right and reduce the amount of ${\text{H}_3\text{O}}^{+}$ in the solution.

The indicator equilibrium will shift to the right to produce more ${\text{H}_3\text{O}}^{+}$ ions along with the colored indicator ions. The solution will show a pink color.

What's the color of the solution after adding NH₄Cl?

Adding $\text{NH}_4\text{Cl}$ will add to the concentration of ${\text{NH}_4}^{+}$ ions in the solution. Some of the ${\text{NH}_4}^{+}$ ions will combine with $\text{OH}^{-}$ ions to produce $\text{NH}_4\text{OH}$ .

The equilibrium between $\text{OH}^{-}$ and ${\text{H}_3\text{O}}^{+}$ ions will shift to the left to produce more of both ions.

${\text{OH}}^{-}\;(aq) + {\text{H}_3\text{O}}^{+} \;(aq) \to 2\; \text{H}_2\text{O} \;(l)$

The indicator equilibrium will shift to the left as the concentration of ${\text{H}_3\text{O}}^{+}$ increases. There will be less colored ions and more colorless molecules in the test tube. The pink color will fade.

7 0

3 years ago

The mass percent of solute in a solution containing 3.73 g KBr dissolved in 131 g of H2O is:

Elina [12.6K]

$\huge \underbrace \mathfrak \red{Answer}$

28%

Explanation:

mass of solute(KBr) = 3.73g

mass of solvent(H2O) = 131g

mass of solution = mass of solute + mass of solvent

= 3.73 + 131

= 134.73g

$\sf \large {mass \: percentage = \frac{mass \: of \: solute}{mass \: of \: solvent} \times 100} \\ \\ \sf mass \: percentage = \frac{3.73}{134.73} \times 100 \\ \\ \sf mass \: percentage = 0.028 \times 100 \\ \\ \sf mass \: percentage = 28\%$

7 0

2 years ago

What is the volume of 0.20 moles of helium at STP?

stealth61 [152]

The volume of 0.20 moles of helium at STP is 4.5 liters.

Explanation:

Given:

Number of moles = 0.20 moles

To Find:

The volume of Helium at STP =?

Solution:

According to ideal gas law

PV = nRT

where

P is pressure,

V is volume,

n is the number of moles

R is the gas constant, and

T is temperature in Kelvin.

The question already gives us the values for p and T ,because helium is at STP. This means that temperature is 273.15 K and pressure is 1 atm .

We also already know the gas constant. In our case, we'll use the value of

0.08206 L atm/K mol since these units fit the units of our given values the best

On substituting these values we get

$1 atm \times V = 0.20 moles \times 0.08206 L atm/K mol$

$V = \frac{0.20 moles \times 0.08206 L atm/K mol }{ 1 atm}$

$V = \frac{4.482}{1}$

V = 4.5 Liters

7 0

3 years ago

The vapor pressure of water at 25.0°C is 23.8 torr. Determine the mass of glucose (molar mass = 180 g/mol) needed to add to 500.

mrs_skeptik [129]

According to Raoult's law the relative lowering of vapour pressure of a solution made by dissolving non volatile solute is equal to the mole fraction of the non volatile solute dissolved.

the relative lowering of vapour pressure is the ratio of lowering of vapour pressure and vapour pressure of pure solvent

$\frac{p^{0-}p}{p^{0}}=x_{B}$