When doing lab experiment you must always ,to prevent lab accient s?

43. Use Table 3-1 to identify a substance that undergoes a

LuckyWell [14K]

Answer:

Oxygen, and from solid to liquid. This is because oxygen's melting point is at -218°C. Melting point refers to the temperature where heat causes particles to vibrate with sufficient energy to break the solid structure, so for oxygen this means it's being turned into a liquid.

4 0

3 years ago

A non-mechanical, rigid, and fully insulated mixing tank is used to combine two inflows to produce wet steam. One inflow consist

Bogdan [553]

Explanation:

As it is given that stream A is super heated. From stream tables, we get that specific enthalpy, ( $h_{A}$ ) is 3054.29 kJ/kg.

For stream B, it is saturated water at 25 degree celsius. It's $h_{B}$ is 2546.54 kJ/kg.

Stream C, data will be as follows.

P = 200 kPa, $\chi$ = 0.9

So, $h_{c}$ = $h_{f} + \chi \times h_{fg}$

= 504.47 + 0.9 \times 2201.7

= 2486 kJ/kg

Now, energy balance formula will be as follows.

$m_{A}h_{A} + m_{B}h_{B}$ = $(m_{A} + m_{B})h_{c}$

$3 \times 3054.29 + m_{B} \times 2546.54$ = $(3 + m_{B}) \times 2486$

$m_{B}$ = 28.16 kg/s

Hence, inflow of saturated liquid is 28.16 kg/s. According to steam table, temperature of wet steam is $120.23^{o}C$

Mass flow rate of out flow is 31.16 kg/s.

7 0

4 years ago

In a titration of 35.00 mL of 0.737 M H2SO4, __________ mL of a 0.827 M KOH solution is required for neutralization.

elena55 [62]

Answer:

In a titration of 35.00 mL of 0.737 M H₂SO₄, 62.4 mL of a 0.827 M KOH solution is required for neutralization.

Explanation:

The balanced reaction is

H₂SO₄ + 2 KOH ⇒ 2 H₂O + K₂SO₄

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) 1 mole of H₂SO₄ is neutralized with 2 moles of KOH.

The molarity M being the number of moles of solute that are dissolved in a given volume, expressed as:

$Molarity=\frac{number of moles}{volume}$

in units of $\frac{moles}{liter}$

then the number of moles can be calculated as:

number of moles= molarity* volume

You have acid H₂SO₄

35.00 mL= 0.035 L (being 1,000 mL= 1 L)
Molarity= 0.737 M

Then:

number of moles= 0.737 M* 0.035 L

number of moles= 0.0258

So you must neutralize 0.0258 moles of H₂SO₄. Now you can apply the following rule of three: if by stoichiometry 1 mole of H₂SO₄ are neutralized with 2 moles of KOH, 0.0258 moles of H₂SO₄ are neutralized with how many moles of KOH?

$moles of KOH=\frac{0.0258moles of H_{2} SO_{4}*2 moles of KOH }{1mole of H_{2} SO_{4}}$