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Dennis_Churaev [7]
3 years ago
9

An investigator is gathering evidence and picks up a shirt that is covered in blood and is not yet dry. After bagging the eviden

ce, what should she do next?
Group of answer choices

Pick up another piece of evidence and put it in the same bag.

Put that evidence inside of a paper bag.

Gather more evidence.

Change her gloves.
Chemistry
1 answer:
ratelena [41]3 years ago
8 0

Answer:

She should search for DNA

Explanation:

You might be interested in
What is the mass of an electron A)0 B)1 C)2 D)50
shepuryov [24]

Answer:

A)0

Explanation:

As the electron is quite small, its true mass changes as it moves, and we call that the relativistic mass.

3 0
3 years ago
WS Percent yield don’t understand how to do would appreciate the help
Grace [21]

Answer:

1. Theoretical yield of NaOH is 22.72 g

2. Percentage yield of NaOH = 22.14%

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

NaHCO₃ —> NaOH + CO₂

From the balanced equation above,,

1 mole of NaHCO₃ decomposed to produce 1 mole (i.e 40 g) of NaOH and 1 mole (i.e 44.01 g) of CO₂.

Next, we shall determine the number of mole of NaHCO₃ that will decompose to produce 25 g of CO₂. This can be obtained as follow:

From the balanced equation above,,

1 mole of NaHCO₃ decomposed to produce 44.01 g of CO₂.

Therefore, Xmol of NaHCO₃ will decompose to 25 g of CO₂ i.e

Xmol of NaHCO₃ = 25 / 44.01

Xmol of NaHCO₃ = 0.568 mole

1. Determination of the theoretical yield of NaOH.

From the balanced equation above,,

1 mole of NaHCO₃ decomposed to produce 40 g of NaOH.

Therefore, 0.568 mole of NaHCO₃ will decompose to produce = 0.568 × 40 = 22.72 g of NaOH.

Thus, the theoretical yield of NaOH is 22.72 g

2. Determination of the percentage yield of NaOH.

Theoretical yield of NaOH = 22.72 g

Actual yield of NaOH = 5.03 g

Percentage yield of NaOH =?

Percentage yield = Actual yield /Theoretical yield × 100

Percentage yield = 5.03 / 22.72 × 100

Percentage yield of NaOH = 22.14%

4 0
3 years ago
The empirical formula of a molecule is C2H6. In an experiment, the Molar mass of the molecule was determined to be 90.21g/mol. U
Firlakuza [10]

Answer:

C₆H₁₈

Explanation:

Let's say x is the subscript of carbon and y is the subscript of hydrogen.  We know from the empirical formula that the ratio of x to y is 2 to 6.

x / y = 2 / 6

We also know from the molar mass that:

12.01x + 1.01y = 90.21

Solving the system of equations:

2y = 6x

y = 3x

12.01x + 1.01(3x) = 90.21

12.01x + 3.03x = 90.21

15.04x = 90.21

x = 6

y = 3x

y = 18

The molecular formula is therefore C₆H₁₈.

4 0
3 years ago
Kidney stones are caused by the precipitation of either calcium oxalate, Ca(C2O4), or calcium phosphate, Ca3(PO4)2, in the kidne
krek1111 [17]

Answer:

1.1 × 10⁻⁶ M

Explanation:

Step 1: Given and required data

  • Concentration of Ca²⁺ ([Ca²⁺]): 2.5 mM = 2.5 × 10⁻³ M
  • Calcium oxalate solubility product constant (Ksp): 2.7 × 10⁻⁹

Step 2: Write the balanced equation for the solution reaction of calcium oxalate

CaC₂O₄(s) ⇄ Ca²⁺(aq) + C₂O₄²⁻(aq)

Step 3: Calculate the concentration of the oxalate ion to begin the precipitation of calcium oxalate

We will use the Ksp of calcium oxalate.

Ksp = 2.7 × 10⁻⁹ = [Ca²⁺].[C₂O₄²⁻]

[C₂O₄²⁻] = Ksp / [Ca²⁺]

[C₂O₄²⁻] = 2.7 × 10⁻⁹ / 2.5 × 10⁻³

[C₂O₄²⁻] = 1.1 × 10⁻⁶ M

3 0
3 years ago
Rosa eats a peanut butter sandwich for lunch. Peanut butter contains a lot of protein, and bread is mostly starch. Rosa plans to
tamaranim1 [39]

Answer: What does she need from the food she ate and the air she breathes so that she can go on her run?

A. Rosa needs carbohydrates rich food (bread) to carry out her jogging activity. Protein-rich food before exercise is not recommended unless she is on a weight loss program (diet plan).

B. Rosa needs oxygen to perform aerobic respiration, which is required for maximum release of energy (36 molecules per reaction run). Anaerobic reactions yield less energy (2 molecules of ATP per reaction run) and are not recommended.

How do Rosa's body systems work together to get the molecules she needs into her cells?

Rosa's body cells need carbohydrates (glucose) and oxygen to perform aerobic respiration for the release of maximum energy. The glucose and oxygen molecules are provided to the cells via diffusion into the bloodstream. During exercise/jogging, complex molecules of carbohydrates such as starch (present in bread) are broken down into simple molecules (glucose) which are diffused into the blood. Likewise, a high amount of oxygen is provided to the body's cells via diffusion in blood, which is carried out by the faster movement of lungs and heart. The combined action results in the supply of both types of molecules to enter the cell where mitochondria use these substrates to produce energy molecules (ATPs).

How do hair cells use these molecules to release energy for her body to run?

The substrates (glucose and oxygen) enters the bloodstream and then taken up to the cell. Then they are provided to the mitochondria for the release of energy in the form of ATP. This is why mitochondria are known as the powerhouse of the cells. Within the cell, energy is released in a three-step process, i.e. glycolysis, the Krebs cycle, and oxidative phosphorylation. Here glucose reacts with oxygen. In the end, aerobic respiration per reaction run produces 36 molecules of ATP which are sufficient to meet intensive energy needs. During excrcise, the supply of oxygen and glucose is also faster due to faster lungs and heart actions.

PS: Anaerobic respiration cannot meet energy demands faster because the reaction produces only 2 ATP molecules per reaction run.

Explanation:

6 0
3 years ago
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