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Ostrovityanka [42]
3 years ago
6

Which of the following is not an indication of a chemical change?

Chemistry
1 answer:
Sauron [17]3 years ago
5 0

Answer:

C. precipitate formation.

Explanation:

options C is correct answer.

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Penicillin is hydrolyzed and thereby rendered inactive by penicillinase, an enzyme present in some resistant bacteria. The mass
Arisa [49]

Answer:

The turnover number is the maximum substrate quantitiy converted to product per enzyme and per second. It can be calculate as follows:

k_c = \frac{V_{max}}{[E]} with [E] active enzyme concentration.

In this case we have Vmax an data to calculate [E]

moles of E=\frac{10^{-9}g}{29600 g/mol}=3.38*10^{-14}

[E]=\frac{3.38*10^{-14}}{0.01 L}=3.38*10^{-12} M

Now k_c=\frac{6.8*10^-10}{3.38*10^{-12}}=201.28 min^{-1}

it is not like any option.

If we assume that V_{max} have the non usual units of mol L^{-1} min^{-1} and it is 6.8*10^-10 mol min^{-1}

So we need divide by the moles of E (in place of [E])

Now k_c=\frac{6.8*10^-10}{3.38*10^{-14}}=20128 min^{-1} = 335 s{-1}

(pass from min^{-1} to s^{-1} dividing by 60)

4 0
3 years ago
Which colorless and odorless gas, produced by radioactive decay of Uranium-238, is considered to be a cancer-causing agent?
alexdok [17]
<span>The correct answer is b. Radon. Oxygen, Hyrdrogen, and Boron, are not radioactivel ike Radon and it regenerates quickly meaning that even though it has a short half-life period, it stays for a long time once released. It also has no taste so it's difficult to notice without proper gear because you can't feel it.</span>
7 0
4 years ago
A substance formed when two<br> or more chemical elements are<br> chemically bonded together?
Ronch [10]

Answer: a piece of pure matter which we can see from our naked eye is termed as a substance

Explanation:

every substance has physical and chemical properties like;

                               diamond ,water ,pure sugar ,table salt e.t.c

an element is a substance made up of same type of atoms having same atomic number[protons],and cannot be easily decomposed in to a single substance by ordinary chemical reaction example,.....

                                               gold,copper,zinc and some are in liquid form like mercury,bromine and some are in gases for example, hydrogen ,oxygen, nitrogen

6 0
3 years ago
How many moles of sand (SiO2) are in 30 g of sand?
anastassius [24]
<h3>Answer:</h3>

0.50 mol SiO₂

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

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

  1. Brackets
  2. Parenthesis
  3. Exponents
  4. Multiplication
  5. Division
  6. Addition
  7. Subtraction
  • Left to Right

<u>Chemistry</u>

<u>Atomic Structure</u>

  • Reading a Periodic Table
  • Using Dimensional Analysis
<h3>Explanation:</h3>

<u>Step 1: Define</u>

30 g SiO₂ (sand)

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

Molar Mass of Si - 28.09 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of SiO₂ - 28.09 + 2(16.00) = 60.09 g/mol

<u>Step 3: Convert</u>

  1. Set up:                                \displaystyle 30 \ g \ SiO_2(\frac{1 \ mol \ SiO_2}{60.09 \ g \ SiO_2})
  2. Multiply/Divide:                  \displaystyle 0.499251 \ mol \ SiO_2

<u>Step 4: Check</u>

<em>Follow sig figs and round. We are given 2 sig figs.</em>

0.499251 mol SiO₂ ≈ 0.50 mol SiO₂

5 0
3 years ago
Read 2 more answers
Consider the two electron arrangements for neutral atoms A and B. What is the atomic number of A?
Andreas93 [3]
Your answer is B: The outer electron of Adam B has moved to a higher energy state
8 0
3 years ago
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