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3 years ago

What are two functions of the cell membrane

Chemistry

1 answer:

Nimfa-mama [501]3 years ago

5 0

Answer:

1 It gives the cell its structure

2 It regulates the materials that enter and leaves the cell

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Assuming that the bath contains 250.0 g of water and that the calorimeter itself absorbs a negligible amount of heat, calculate

Anvisha [2.4K]

Answer:

$-3272$ kJ/mol

Explanation:

Given and known facts

Mass of Benzene $= 0.187$ grams

Mass of water $= 250$ grams

Standard heat capacity of water $= 4.18$ J/g∙°C

Change in temperature ΔT $= 7.48$ °C

Heat

$=250 * 4.18 * 7.48\\=7816.6 \\=7.82$

Heat released by benzine is - 7.82 kJ

Now, we know that

$0.187$ grams of benzene release $= -7.82$ kJ heat

So, $1$ g benzine releases

$\frac{ -7.82 }{0.187}\\= -41.8$

kJ/g

$0.187 * \frac{1}{78.108}=0.00239$ mol C6H6

Heat released

$= \frac{-7.82}{ 0.00239}$

$=-3272$ kJ/mol

4 0

2 years ago

what is an empirical formulaWhat is the percent composition by mass of nitrogen in (NH4)2CO3 (gram-formula mass = 96.0 g/mol)?

Margarita [4]

Answer:

Percentage composition = 14.583%

Explanation:

In chemistry, the emprical formular of a compound is the simplest formular a compound can have. It shows the simplest ratio in which the elements are combined in the compound.

Percentage composition by mass of Nitrogen

Nitrogen = 14g/mol

In one mole of the compound;

Mass of Nitrogen = 1 mol * 14g/mol = 14g

Mass of compound = 1 mol * 96.0 g/mol = 96

Percentage composition of Nitrogen = (Mass of Nitrogen / Mass of compound) * 100

percentage composition = 14/96 * 100

Percentage composition = 0.14583 * 100

Percentage composition = 14.583%

3 0

2 years ago

In some developing nations, the percentage of animal protein from fish in the diet can be as high as _____.

Makovka662 [10]

Answer:

20%

Explanation:

The fish consumption has had lot of variations in the past few centuries, most noticeably in the last century. Initially it was the richer countries that had population which was consuming the most animal protein from fish in the world, while the developing nations had less. Things have changed though, especially during the 1990's, when the developing nations experienced a rapid increase in the consumption of fish. This was largely due to the growing standard and the availability of fish, so in some of the developing nations the percentage of animal protein from fish reached around 20%.

5 0

2 years ago

Calculate the empirical formula for DCBN, given that the percent composition is 48.9%C, 1.76%H, 41.2%Cl, and 8.15%N.

sweet [91]

Answer:

empirical formula is C7H3NCl2

Explanation:

too much work too explain and im lazy

5 0

3 years ago

How many moles of copper are in 1.51 x 1024 Cu atoms?

kkurt [141]

<h3>Answer:</h3>

2.51 mol Cu

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

<u>Chemistry</u>

<u>Atomic Structure</u>

Using Dimensional Analysis
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<h3>Explanation:</h3>

<u>Step 1: Define</u>

1.51 × 10²⁴ atoms Cu

<u>Step 2: Identify Conversions</u>

Avogadro's Number

<u>Step 3: Convert</u>

Set up: $\displaystyle 1.51 \cdot 10^{24} \ atoms \ Cu(\frac{1 \ mol \ Cu}{6.022 \cdot 10^{23} \ atoms \ Cu})$
Multiply/Divide: $\displaystyle 2.50747 \ mol \ Cu$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

2.50747 mol Cu ≈ 2.51 mol Cu

8 0

2 years ago