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3 years ago

3. Students measured the mass of the reactants and products for a combustion reaction they observed.

Chemistry

1 answer:

coldgirl [10]3 years ago

4 0

Answer:

A. Students made a measurement error, because ending with more products is impossible.

Explanation:

The law of conversation of matter tells us that in a chemical reaction, matter is never created or destroyed, it's simply converted from one form to another. So the mass of reactants should always equal the mass of the products in a chemical reaction. If there is excess mass in the product, the students have made an error of some kind.

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Prior to hosting an international soccer match, the local soccer club needs to replace the artifical turf on their field with gr

GuDViN [60]

Answer:

It will cost $68,620.5 to the club to add the grass turf to their field.

Explanation:

length of the field = l = 0.102 km = 0.102 × 1000 m

( 1km = 1000 m)

Width of the field w = 0.069 km = 0.069 × 1000 m

Area of the field , A= l × w

$A=0.102\times 1000 m\times 0.069\times 1000 m=7,038 m^2$

Cost of grass turfing = $9.75 \$/m^2$

Cost of grass turfing on field of $7,038 m^2$ :

$=7,038 m^2\times 9.75 \$/m^2=\$68,620.5$

It will cost $68,620.5 to the club to add the grass turf to their field.

4 0

3 years ago

Are sharks mammals pls answer

ddd [48]

Answer:

no they are a fish

Explanation:

8 0

3 years ago

Consider the hypothetical reaction 3A + 4B → C + 2D Over an interval of 2.50 s the average rate of change of the concentration o

faust18 [17]

Answer:

Final [B] = 1.665 M

Explanation:

3A + 4B → C + 2D

Average rection rate = 3[A]/Δt = 4[B]/Δt = [C]/Δt = 2[D]/Δt

0.05600 M/s = 4 [B]/ 2.50 s

[B] = 0.035 M (concentration of B consumed)

Final [B] = initial [B] - consumed [B]

Final [B] = 1.700 M - 0.035 M

Final [B] = 1.665 M

3 0

3 years ago

How many grams of sodium acetate ( molar mass = 83.06 g/mol ) must be added to 1.00 Liter of a 0.200 M acetic acid solution to m

Pie

<u>Answer:</u> The mass of sodium acetate that must be added is 30.23 grams

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Molarity of acetic acid solution = 0.200 M

Volume of solution = 1 L

Putting values in above equation, we get:

$0.200M=\frac{\text{Moles of acetic acid}}{1L}\\\\\text{Moles of acetic acid}=(0.200mol/L\times 1L)=0.200mol$

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{salt}]}{[\text{acid}]})$

$pH=pK_a+\log(\frac{[CH_3COONa]}{[CH_3COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of acetic acid = 4.74

$[CH_3COONa]=?mol$

$[CH_3COOH]=0.200mol$

pH = 5.00

Putting values in above equation, we get:

$5=4.74+\log(\frac{[CH_3COONa]}{0.200})$

$[CH_3COONa]=0.364mol$

To calculate the mass of sodium acetate for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of sodium acetate = 83.06 g/mol

Moles of sodium acetate = 0.364 moles

Putting values in above equation, we get:

$0.364mol=\frac{\text{Mass of sodium acetate}}{83.06g/mol}\\\\\text{Mass of sodium acetate}=(0.364mol\times 83.06g/mol)=30.23g$

Hence, the mass of sodium acetate that must be added is 30.23 grams

7 0

3 years ago

How many grams of CrSO3 are in 2.4 moles of CrSO3

castortr0y [4]

Answer: 316.8 g CrSO3

Explanation: Solution:

2.4 moles CrSO3 x 132 g CrSO3 / 1 mole CrSO3 = 316.8 g CrSO4

The conversion factor is 1 mole of CrSO4 is equal to its molar mass which is 132 g CrSO3

4 0

3 years ago