All categories

3 years ago

Which change does not increase the speed of reaction between zinc and hydrochloric acid?

Chemistry

2 answers:

tankabanditka [31]3 years ago

5 0

When solid zinc is dropped into hydrochloric acid solution, it falls to the bottom due to its higher density. The reaction occurs at the surface of the zinc metal and generates hydrogen gas that bubbles up through the solution. You can tell that the rate increases because the rate of bubble formation increases. This will naturally occur because the reaction is exothermic and will warm the solution around the zinc metal. The higher temperature will increase the reaction rate.

If you want a more quantitative analysis of reaction rate, you can perform the experiment in a eudiometer tube that is inverted and completely filled with liquid. As the hydrogen gas collects in the tube you can measure its accumulated volume with time. That will allow you to determine an approximate kinetic rate law for the process. The rate law determined in this manner will suffer from error due to temperature and surface area changes as well as gas volume error due to water vapor. But, it is an interesting application of chemical kinetics.

Mademuasel [1]3 years ago

3 0

Any factor that causes molecules to collide more frequently speeds up the reaction rate. This is achieved by an increase of the reactants concentration, surface area, raised temp. , raised pressure of gaseous reactant, or an addition of catalysts to the reactant

You might be interested in

Use the tabulated half-cell potentials to calculate the equilibrium constant (K) for the following balanced redox reaction at 25

o-na [289]

The equation Eºcell = 0.0592/n logK must be used to find n and also Eºcell
2 Al(s) + 3 Mg2+(aq) → 2 Al3+(aq) + 3 Mg(s) Al3+ +3e- --> Al Eº = -1.66 V Mg2+ +2e- -->Mg Eº = -2.37V
To balance the equation, 6 moles of electrons must be transferred (2 Al and 3 Mg). This will be the value of n in the equation.
To find Eºcell, you need the reduction potentials which should be given in a table, and given above. Eºcell = -1.66 - (-2.37) = 0.71 V log K = Eºcell x n/0.0592 = 0.71 x 6/0.0592 log K = 71.95 K = 10^71.95 K = 1.1x10^72

6 0

3 years ago

112 g of aluminum carbide react with 174 g water to produce methane and aluminum hydroxide in the reaction shown below.

dolphi86 [110]

<u>Answer:</u> 4.999 moles of excess reactant will be left over.

<u>Explanation:</u>

Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.

Excess reagent is defined as the reagent which is left behind after the completion of the reaction.

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Given mass of aluminium carbide = 112 g

Molar mass of aluminium carbide = 143.96 g/mol

Putting values in equation 1:

$\text{Moles of aluminium carbide}=\frac{112g}{143.96g/mol}=0.778mol$

For the given chemical reaction:

$2Al_4C_3(s)+12H_2O(l)\rightarrow 3CH_4(g)+4Al(OH)_3(s)$

By the stoichiometry of the reaction:

2 moles of aluminium carbide reacts with 12 moles of water

So, 0.778 moles of aluminium carbide will react with = $\frac{12}{2}\times 0.778=4.668 mol$ of water

Given mass of water = 174 g

Molar mass of water = 18 g/mol

Putting values in equation 1:

$\text{Moles of water}=\frac{174g}{18g/mol}=9.667mol$

Moles of excess reactant (water) left = 9.667 - 4.668 = 4.999 moles

Hence, 4.999 moles of excess reactant will be left over.

8 0

2 years ago

several dams on the colorado river in texas produce electricity through hydropower. what is an advantage of this type of energy

Ivanshal [37]

Explanation:

hydropower energy is:

-renewable

-clean (doesn't produce toxins or emit harmful gases into the atmosphere)

-environment friendly

-cheap once installed

3 0

2 years ago

A 100.0-mL sample of 1.00 M NaOH is mixed with 50.0 mL of 1.00 M H2SO4 in a large Styrofoam coffee cup calorimeter fitted with a

worty [1.4K]

Answer:

THE ENTHALPY CHANGE IN KJ/MOLE IS +114 KJ/MOLE.

Explanation:

Heat = mass * specific heat capacity * temperature rise

Total volume = 100 + 50 = 150 mL

Total mass = density * volume

Total mass = 1 * 150 mL = 150 g

So therefore, the heat evolved during the reaction is:

Heat = 150 * 4.18 * ( 31.4 - 22.3)

Heat = 150 * 4.18 * 9.1

Heat = 5705.7 J

Equation for the reaction:

2 NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + 2 H2O(l)

From the equation, 2 moles of NaOH reacts with 1 mole of H2SO4 to produce 1 mole of Na2SO4 and 2 moles of water

50 mL of 1 M of H2SO4 contains

50 * 1 / 1000 mole of acid

= 0.05 mole of acid

The production of 1 mole of water evolved 5705.7 J of heat and hence the enthalpy changein kJ per mole will be:

0.05 mole of H2SO4 produces 5705.7 J of heat

1 mole of H2SO4 will produce 5705.7 / 0.05 J

= 114,114 J / mole

In kj/mole = 114 kJ/mole.

Hence, the enthalpy change of the reaction in kJ /mole is +114 kJ/mole.

5 0

3 years ago

Write any three acids which are used in our daily life. Also, write an application of each

lidiya [134]

Sodium fluoride- to brush teeth
Citric acid- orange juice for breakfast
Sodium hydroxide- cleaning agent

3 0

2 years ago