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3 years ago

How many elements are there

Chemistry

2 answers:

Kobotan [32]3 years ago

8 0

Explanation:

there are 118 elements.

Levart [38]3 years ago

6 0

Answer:

there r 118 elements in periodic table..

hope it helps.

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What is the complement DNA strand to GTACCTAGGT?

Serga [27]

CATGGATCCA for future reference this is considered biology, you may get a quicker response if you categorize it as such :)

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3 years ago

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How do atoms form a new substance?

lubasha [3.4K]

By sharing electeons with each other
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3 years ago

0.415 g of an unknown triprotic acid are used to make a 100.00 mL solution. Then 25.00 mL of this solution is transferred to an

Arturiano [62]

Answer:

Explanation:

Initial burette reading = 1.81 mL

final burette reading = 39.7 mL

volume of NaOH used = 39.7 - 1.81 = 37.89 mL .

37.89 mL of .1029 M NaOH is used to neutralise triprotic acid

No of moles contained by 37.89 mL of .1029 M NaOH

= .03789 x .1029 moles

= 3.89 x 10⁻³ moles

Since acid is triprotic , its equivalent weight = molecular weight / 3

No of moles of triprotic acid = 3.89 x 10⁻³ / 3

= 1.30 x 10⁻³ moles .

8 0

3 years ago

Hot water enters a double-pipe counter-flow water-to-oil heat exchanger at 220°7 and leaves a 100°F. Oil enters at 70°F and leav

il63 [147K]

Answer:

Oil has the smaller heat capacity. The effectiveness of the heat exchanger is 0.80.

Explanation:

Part 1:

In order to know which fluid has the smaller heat capacity we need to consider the heat equation below:

Q = CΔT, where Q is the heat exchanged, C is the heat capacity and ΔT is the variation in temperature.

As the heat exchange is the same for both fluids, the smaller the temperature variation, the smaller the heat capacity.

Water: ΔT = 120 °F

Oil: ΔT = 80 °F

Therefore, oil is the fluid with the smallest heat capacity.

Part 2:

The effectiveness of a counter-flow heat exchanger is given by the equation bellow:

$E = \frac{Th1 - Th2}{Th1 - Tc1} \\$

Th1: initial temperature of the hot fluid

Th2: final temperature of the hot

Tc1: initial temperature of the cold fluid

$E = \frac{220 - 100}{220 - 70} \\E = 0.8$

7 0

3 years ago

If the solubility of sodium chloride is 36 grams per 100 grams of water, which of the following solutions would be considered un

Murrr4er [49]

Answer: If the solubility of sodium chloride is 36 grams per 100 grams of water then 5.8 moles of NaCl dissolved in 1 L of water solution would be considered unsaturated.

Explanation:

A solution which contains the maximum amount of solute is called a saturated solution. Whereas a solution in which more amount of solute is able to dissolve is called an unsaturated solution.

Now, the number of moles present in 36 g of NaCl (molar mass = 58.4 g/mol) is as follows.

$No. of moles = \frac{mass}{molar mass}\\= \frac{36 g}{58.4 g/mol}\\= 0.616 mol$

This shows that solubility of sodium chloride is 36 grams per 100 grams of water means a maximum of 0.616 mol of NaCl will dissolve in 100 mL of water.

So, a solution in which number of moles of NaCl are less than 0.616 mol per 100 mL then the solution formed will be an unsaturated solution.

As 5.8 moles of NaCl dissolved in 1 L (or 1000 mL) of water. So, moles present in 100 mL are calculated as follows.

$Moles = \frac{5.8 mol}{1000 mL} \times 100 mL\\= 0.58 mol$

Moles present in 100 mL of water for 3.25 moles of NaCl dissolved in 500 ml in water are as follows.

$Moles = \frac{3.25 mol}{500 mL} \times 100 mL\\0.65 mol$

Moles present in 100 mL of water for 1.85 moles of NaCl dissolved in 300 ml of water are as follows.

$Moles = \frac{1.85 mol}{300 mL} \times 100 mL\\= 0.616 mol$

Thus, we can conclude that if the solubility of sodium chloride is 36 grams per 100 grams of water then 5.8 moles of NaCl dissolved in 1 L of water solution would be considered unsaturated.

8 0

3 years ago

How many elements are there​

How many elements are there