Answer:
4.5 kilograms of silicon dioxide is required to produce 3.00 kg of SiC.
Explanation:
The balanced equation for the reaction between silicon dioxide and carbon at high temperature is given as:

1 mole silicon dioxide reacts with 3 moles of carbon to give 1 moles of silicon carbide and 2 moles of carbon monoxide.
Mass of SiC = 3.00kg = 3000.00 g
1 kg = 1000 g
Molecular mass of SiC = 40 g/mol
Moles of SiC = 
According to reaction, 1 mole of SiC is produced from 1 mole of silicon dioxide.
Then 75 moles of SiC will be produce from:
of silicon dioxide.
mass of 75 moles of silicon dioxde:

4.5 kilograms of silicon dioxide is required to produce 3.00 kg of SiC.
Answer:
31.5 mL of a 2.50M NaOH solution
Explanation:
Molarity (M) is an unit of concentration defined as moles of solute (In this case, NaOH), per liter of solvent. That is:
Molarity = moles solute / Liter solvent
If you want to make 525mL (0.525L) of a 0.150M of NaOH, you need:
0.525L × (0.150mol / L) = <em>0.07875 moles of NaOH</em>
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If you want to obtain these moles from a 2.50M NaOH solution:
0.07875mol NaOH × (1L / 2.50M) = 0.0315L = <em>31.5 mL of a 2.50M NaOH solution</em>
Claim: Earth's atmospheric CO2 levels were measured over the past 1000 years and correlated with average world temperatures. The data demostrate that Earth's temperature did not change during the period CO2 levels were steady. But the past 100 years show a dramatic rise in CO2 levels, with a corresponding rise in world temperatures. The CO2 rise can be traced back to the start of the industrial revolution, when machines began doing much of the work. These machine burn fossil fuels and the increased CO2 levels have led to a dramatic rise in world temperatures. The data clearly show the importance of reducing fossil fuel useage, as well as other CO2 emitters. A world of incresing temperatures will lead to greater natural disasters, such as storms, flooding, hurricanes, and drought - all of which upset the ecological balance of the planet.
Answer:
False
Explanation:
The urine is produced in the kidneys, each one of the kidneys is connected to a ureter. The ureter is a tube that propels the excreted urine to the urinary bladder. The urinary bladder is a deposit for the urine, here is collected and stored before disposal. After the urinary bladder, the urine goes through the urethra, which is a tube, to exit the body.