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Aleks04 [339]
3 years ago
6

Whenever ___ energy is needed

Chemistry
1 answer:
vfiekz [6]3 years ago
5 0
Well...........thanks for posting anyway. 
You might be interested in
A/1 * B/C =D
Korvikt [17]

Exchange rate is 1.5 guilders for every 2.4 florins

The conversion factor will be

1.5 guilders / 2.4 florins = 2.4 florins / 1.5 guilders = 1

so if we wish to convert 4 guilders to florins we will use following conversion factor

2.4 florins / 1.5 guilders = B / C

D = 4guilders X 2.4 florins / 1.5 guilders = 6.4 florins

7 0
3 years ago
Explain how a heat pump is used to both heat and cool a building?
mel-nik [20]

Answer:

Like your refrigerator, heat pumps use electricity to move heat from a cool space to a warm space, making the cool space cooler and the warm space warmer. ... The most common type of heat pump is the air-source heat pump, which transfers heat between your house and the outside air.

Explanation:

5 0
3 years ago
Read 2 more answers
One brand of extra-strength antacid tablets contains 750 mg of calcium carbonate (100 g/mol) in each tablet. Stomach acid is ess
konstantin123 [22]

Answer:

One tablet can neutralize 150 mL of stomach acid at a pH of 1.0

Explanation:

Step 1: Data given

Mass of calcium carbonate = 750 mg = 0.75 grams

Molar mass of CaCO3 = 100 g/mol

pH = 1.0

Step 2: The balanced equation

2HCl  +  CaCO3 →  CaCl2  +  H2CO3

Step 3: Calculate molarity of HCl

pH = -log[H+] = 1

[H+] = 0.1 M = 0.10 mol/L

Step 4: Calculate moles of CaCO3

Moles CaCO3 = 0.75 grams / 100g/mol

Moles CaCO3 = 0.0075 mol

Step 5: Calculate moles of HCl

For 2 moles HCl we need 1 mol CaCO3 to produce CaCl2 and 1 mole of H2CO3

For 0.0075 moles of CaCO3 we have 2*0.0075 = 0.015 moles HCl

Step 6: Calculate volume of HCl

Volume = moles /molarity

Volume = 0.015 moles / 0.1 M

Volume = 0.15 L = 150 mL

One tablet can neutralize 150 mL of stomach acid at a pH of 1.0.

6 0
3 years ago
A solution is made by mixing equal masses of methanol, CH4O, and ethanol, C2H6O. Determine the mole fraction of each component t
Serggg [28]

Answer: mole fraction of methanol = 0.590

mole fraction of ethanol = 0.410

Explanation:

We are given:

Equal masses of methanol CH_4O and ethanol C_2H_6O are mixed.

let the mass be x g.

Calculating the moles of methanol in the solution, by using the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{xg}{32.04g/mol}

Calculating the moles of ethanol in the solution, by using the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{xg}{46.07g/mol}

To calculate the mole fraction of methanol, we use the equation:

\chi_{methanol}=\frac{n_{methanol}}{n_{methaol}+n_{ethanol}}

\chi_{methanol}=\frac{\frac{xg}{32.04g/mol}}{\frac{xg}{32.04g/mol}+\frac{xg}{46.07g/mol}}=0.590

To calculate the mole fraction of ethanol, we use the equation:

\chi_{ethanol}=\frac{n_{ethanol}}{n_{methaol}+n_{ethanol}}

\chi_{ethanol}=\frac{\frac{xg}{46.07g/mol}}{\frac{xg}{32.04g/mol}+\frac{xg}{46.07g/mol}}=0.410

Thus mole fraction of methanol is 0.590 and mole fraction of ethanol 0.410 in three significant figures.

5 0
2 years ago
5. The element copper has naturally occurring isotopes with mass numbers of 63
natali 33 [55]

Answer:

63.616

Explanation:

DATA

1. first atomic mass;m1=63

  1. second atomic mass;m2=65
  2. first percentage;p1= 69.2%
  3. second percentage me;p2=30.8%
  4. average mass;avg= ?

SOLUTION

avg=<u> (m1)(p1) + (m2)(</u><u>p2</u><u>)</u>

100

avg= <u>(63)(69.2) + (65)(30.8)</u>

100

avg= <u>4</u><u>3</u><u>5</u><u>9</u><u>.</u><u>6</u><u> </u><u>+</u><u> </u><u>2</u><u>0</u><u>0</u><u>2</u>

100

avg= <u>6361.6</u>

100

avg= 63.616

4 0
3 years ago
Read 2 more answers
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