Ask question

Ask question

All categories

2 years ago

10

(50-100 points!) write the unbalanced chemical equation for the following reaction: silicon dioxide + hydrofluoric acid produces

silicon tetrafluoride + water

2 answers:

BlackZzzverrR [31]2 years ago

6 0

Answer:

SiO2 + HF = SiF4 + H2O

andrezito [222]2 years ago

3 0

Answer:

Unbalanced: SiO2 + HF = SiF4 + H2O

Explanation:

Unbalanced: SiO2 + HF = SiF4 + H2O

You might be interested in

Arbon dioxide is dissolved in blood (ph 7.5) to form a mixture of carbonic acid and bicarbonate. Part a neglecting free co2, wha

Aleks04 [339]

Answer : The fraction of carbonic acid present in the blood is 5.95%

Explanation :

The mixture consists of carbonic acid ( H₂CO₃) and bicarbonate ion ( HCO₃⁻). This represents a mixture of weak acid and its conjugate which is a buffer.

The pH of a buffer is calculated using Henderson equation which is given below.

$pH = pKa + log \frac{[Base]}{[Acid]}$

We have been given,

pH = 7.5

pKa of carbonic acid = 6.3

Let us plug in the values in Henderson equation to find the ratio Base/Acid.

$7.5 = 6.3 + log \frac{[base]}{[acid]}$

$1.2 = log \frac{[base]}{[acid]}$

$\frac{[Base]}{[Acid]} = 10^{1.2}$

$\frac{[Base]}{[Acid]} = 15.8$

$[Base] = 15.8 \times [Acid]$

The total of mole fraction of acid and base is 1. Therefore we have,

$[Acid] + [Base] = 1$

But Base = 15.8 x [Acid]. Let us plug in this value in above equation.

$[Acid] + 15.8 \times [Acid] = 1$

$16.8 [Acid] = 1$

$[Acid] = \frac{1}{16.8}$

$[Acid] = 0.0595$

[Acid] = 0.0595 x 100 = 5.95 %

The fraction of carbonic acid present in the blood is 5.95%

4 0

3 years ago

Read 2 more answers

If a 12-volt battery produces a current of 20 amps, what is the resistance?

mixas84 [53]

Answer:

0.6 Ω

Explanation:

From the question given above, the following data were obtained:

Voltage (V) = 12 V

Current (I) = 20 A

Resistance (R) =?

From Ohm's law,

V = IR

Where:

V => is the voltage

I => is the current

R => R is the resistance

With the above formula, we can obtain the resistance as follow:

Voltage (V) = 12 V

Current (I) = 20 A

Resistance (R) =?

V = IR

12 = 20 × R

Divide both side by 20

R = 12 / 20

R = 0.6 Ω

Thus the resistance is 0.6 Ω

4 0

3 years ago

200 g of solid sodium hydroxide (NaOH) are dissolved in 750 mL of water. What is the concentration of this solution?

Anastaziya [24]

Answer:

6.67 M

Explanation:

Molarity = $\frac{mol}{L}$

<em>Convert 200g NaOH to moles. Convert 750 mL to L.</em>

200 g NaOH x (1 mol/39.998 g) = 5.00025... mol NaOH

750 mL x (1 L/1000 mL) = 0.750 L

<em>Substitute values into the equation.</em>

Molarity = $\frac{5.00025}{0.750}$

Molarity = 6.667... M

Molarity = 6.67 M

8 0

3 years ago

To make a 1.0L dilute of 0.5M from a stock solution of 12M, how much solution will be needed?

Cerrena [4.2K]

Answer:

$V_{concentrated}=0.042L=4.2mL$

Explanation:

Hello,

In this case, since in a dilution process the moles of the solute must remain unchanged, we use the volumes and molarities as shown below:

$M_{diluted}V_{diluted}=M_{concentrated}V_{concentrated}$

Clearly, the concentrated solution is 12M and the diluted solution is 0.5 M, thus, the volume of the concentrated solution we should take is:

$V_{concentrated}=\frac{M_{diluted}V_{diluted}}{M_{concentrated}} =\frac{0.5M*1.0L}{12M}\\ \\V_{concentrated}=0.042L=4.2mL$

Best regards.

6 0

3 years ago

What type of chemical reaction

amm1812

Answer:

Oxidation or Exothermic reaction

Explanation:

Oxidation means gain of oxygen.

Exothermic means loss of heat to combine 2 elements

5 0

3 years ago